diff --git a/frontend/src/dialog/photo/files.vue b/frontend/src/dialog/photo/files.vue
index a4a4bfa32..8ef52a45e 100644
--- a/frontend/src/dialog/photo/files.vue
+++ b/frontend/src/dialog/photo/files.vue
@@ -1,197 +1,201 @@
 <template>
   <div class="p-tab p-tab-photo-files">
     <v-expansion-panel expand class="pa-0 elevation-0 secondary" :value="state">
-      <v-expansion-panel-content v-for="(file, index) in model.fileModels()" :key="index"
-                                 class="pa-0 elevation-0 secondary-light" style="margin-top: 1px;">
-        <template #header>
-          <div class="caption">{{ file.baseName(70) }}</div>
-        </template>
-        <v-card>
-          <v-card-text class="white pa-0">
-            <v-container fluid class="pa-0">
-              <v-layout row wrap fill-height
-                        align-center
-                        justify-center>
-                <v-flex xs12 class="pa-0">
-                  <div class="v-table__overflow">
-                    <table class="v-datatable v-table theme--light photo-files">
-                      <tbody>
-                      <tr v-if="file.Type === 'jpg'">
-                        <td>
-                          <translate>Preview</translate>
-                        </td>
-                        <td>
-                          <v-img :src="file.thumbnailUrl('tile_224')"
-                                 aspect-ratio="1"
-                                 max-width="112"
-                                 max-height="112"
-                                 class="accent lighten-2 elevation-0 clickable"
-                                 @click.exact="openFile(file)"
-                          >
-                          </v-img>
-                        </td>
-                      </tr>
-                      <tr>
-                        <td>
-                          <translate>Actions</translate>
-                        </td>
-                        <td>
-                          <v-btn small depressed dark color="primary-button" class="ma-0 action-download"
-                                 @click.stop.prevent="downloadFile(file)">
-                            <translate>Download</translate>
-                          </v-btn>
-                          <v-btn v-if="features.edit && file.Type === 'jpg' && !file.Primary" small depressed dark color="primary-button"
-                                 class="ma-0 action-primary"
-                                 @click.stop.prevent="primaryFile(file)">
+      <template v-for="(file, index) in model.fileModels()">
+        <v-expansion-panel-content v-if="!file.Missing" :key="index" class="pa-0 elevation-0 secondary-light"
+                                   style="margin-top: 1px;">
+          <template #header>
+            <div class="caption">{{ file.baseName(70) }}</div>
+          </template>
+          <v-card>
+            <v-card-text class="white pa-0">
+              <v-container fluid class="pa-0">
+                <v-layout row wrap fill-height
+                          align-center
+                          justify-center>
+                  <v-flex xs12 class="pa-0">
+                    <div class="v-table__overflow">
+                      <table class="v-datatable v-table theme--light photo-files">
+                        <tbody>
+                        <tr v-if="file.Type === 'jpg'">
+                          <td>
+                            <translate>Preview</translate>
+                          </td>
+                          <td>
+                            <v-img :src="file.thumbnailUrl('tile_224')"
+                                   aspect-ratio="1"
+                                   max-width="112"
+                                   max-height="112"
+                                   class="accent lighten-2 elevation-0 clickable"
+                                   @click.exact="openFile(file)"
+                            >
+                            </v-img>
+                          </td>
+                        </tr>
+                        <tr>
+                          <td>
+                            <translate>Actions</translate>
+                          </td>
+                          <td>
+                            <v-btn small depressed dark color="primary-button" class="ma-0 action-download"
+                                   @click.stop.prevent="downloadFile(file)">
+                              <translate>Download</translate>
+                            </v-btn>
+                            <v-btn v-if="features.edit && file.Type === 'jpg' && !file.Primary" small depressed dark
+                                   color="primary-button"
+                                   class="ma-0 action-primary"
+                                   @click.stop.prevent="primaryFile(file)">
+                              <translate>Primary</translate>
+                            </v-btn>
+                            <v-btn v-if="features.edit && !file.Sidecar && !file.Primary && file.Root === '/'" small
+                                   depressed dark color="primary-button"
+                                   class="ma-0 action-unstack"
+                                   @click.stop.prevent="unstackFile(file)">
+                              <translate>Unstack</translate>
+                            </v-btn>
+                            <v-btn v-if="features.delete && !file.Primary" small depressed dark color="primary-button"
+                                   class="ma-0 action-delete"
+                                   @click.stop.prevent="showDeleteDialog(file)">
+                              <translate>Delete</translate>
+                            </v-btn>
+                          </td>
+                        </tr>
+                        <tr>
+                          <td title="Unique ID">
+                            UID
+                          </td>
+                          <td>{{ file.UID | uppercase }}</td>
+                        </tr>
+                        <tr v-if="file.InstanceID" title="XMP">
+                          <td>
+                            <translate>Instance ID</translate>
+                          </td>
+                          <td>{{ file.InstanceID | uppercase }}</td>
+                        </tr>
+                        <tr>
+                          <td title="SHA-1">
+                            <translate>Hash</translate>
+                          </td>
+                          <td>{{ file.Hash }}</td>
+                        </tr>
+                        <tr v-if="file.Root.length > 1">
+                          <td>
+                            <translate>Storage Folder</translate>
+                          </td>
+                          <td>{{ file.Root | capitalize }}</td>
+                        </tr>
+                        <tr v-if="file.Name">
+                          <td>
+                            <translate>Name</translate>
+                          </td>
+                          <td>{{ file.Name }}</td>
+                        </tr>
+                        <tr v-if="file.OriginalName">
+                          <td>
+                            <translate>Original Name</translate>
+                          </td>
+                          <td>{{ file.OriginalName }}</td>
+                        </tr>
+                        <tr>
+                          <td>
+                            <translate>Size</translate>
+                          </td>
+                          <td>{{ file.sizeInfo() }}</td>
+                        </tr>
+                        <tr v-if="file.Type">
+                          <td>
+                            <translate>Type</translate>
+                          </td>
+                          <td>{{ file.typeInfo() }}</td>
+                        </tr>
+                        <tr v-if="file.Codec">
+                          <td>
+                            <translate>Codec</translate>
+                          </td>
+                          <td>{{ file.Codec | uppercase }}</td>
+                        </tr>
+                        <tr v-if="file.Primary">
+                          <td>
                             <translate>Primary</translate>
-                          </v-btn>
-                          <v-btn v-if="features.edit && !file.Sidecar && !file.Primary && file.Root === '/'" small depressed dark color="primary-button"
-                                 class="ma-0 action-unstack"
-                                 @click.stop.prevent="unstackFile(file)">
-                            <translate>Unstack</translate>
-                          </v-btn>
-                          <v-btn v-if="features.delete && !file.Primary" small depressed dark color="primary-button"
-                                 class="ma-0 action-delete"
-                                 @click.stop.prevent="showDeleteDialog(file)">
-                            <translate>Delete</translate>
-                          </v-btn>
-                        </td>
-                      </tr>
-                      <tr>
-                        <td title="Unique ID">
-                          UID
-                        </td>
-                        <td>{{ file.UID | uppercase }}</td>
-                      </tr>
-                      <tr v-if="file.InstanceID" title="XMP">
-                        <td>
-                          <translate>Instance ID</translate>
-                        </td>
-                        <td>{{ file.InstanceID | uppercase }}</td>
-                      </tr>
-                      <tr>
-                        <td title="SHA-1">
-                          <translate>Hash</translate>
-                        </td>
-                        <td>{{ file.Hash }}</td>
-                      </tr>
-                      <tr v-if="file.Root.length > 1">
-                        <td>
-                          <translate>Storage Folder</translate>
-                        </td>
-                        <td>{{ file.Root | capitalize }}</td>
-                      </tr>
-                      <tr v-if="file.Name">
-                        <td>
-                          <translate>Name</translate>
-                        </td>
-                        <td>{{ file.Name }}</td>
-                      </tr>
-                      <tr v-if="file.OriginalName">
-                        <td>
-                          <translate>Original Name</translate>
-                        </td>
-                        <td>{{ file.OriginalName }}</td>
-                      </tr>
-                      <tr>
-                        <td>
-                          <translate>Size</translate>
-                        </td>
-                        <td>{{ file.sizeInfo() }}</td>
-                      </tr>
-                      <tr v-if="file.Type">
-                        <td>
-                          <translate>Type</translate>
-                        </td>
-                        <td>{{ file.typeInfo() }}</td>
-                      </tr>
-                      <tr v-if="file.Codec">
-                        <td>
-                          <translate>Codec</translate>
-                        </td>
-                        <td>{{ file.Codec | uppercase }}</td>
-                      </tr>
-                      <tr v-if="file.Primary">
-                        <td>
-                          <translate>Primary</translate>
-                        </td>
-                        <td>
-                          <translate>Yes</translate>
-                        </td>
-                      </tr>
-                      <tr v-if="file.Portrait">
-                        <td>
-                          <translate>Portrait</translate>
-                        </td>
-                        <td>
-                          <translate>Yes</translate>
-                        </td>
-                      </tr>
-                      <tr v-if="file.Projection">
-                        <td>
-                          <translate>Projection</translate>
-                        </td>
-                        <td>{{ file.Projection | capitalize }}</td>
-                      </tr>
-                      <tr v-if="file.AspectRatio">
-                        <td>
-                          <translate>Aspect Ratio</translate>
-                        </td>
-                        <td>{{ file.AspectRatio }}</td>
-                      </tr>
-                      <tr v-if="file.MainColor">
-                        <td>
-                          <translate>Main Color</translate>
-                        </td>
-                        <td>{{ file.MainColor | capitalize }}</td>
-                      </tr>
-                      <tr v-if="file.Type === 'jpg'">
-                        <td>
-                          <translate>Chroma</translate>
-                        </td>
-                        <td>{{ file.Chroma }} / 100</td>
-                      </tr>
-                      <tr v-if="file.Error">
-                        <td>
-                          <translate>Error</translate>
-                        </td>
-                        <td>{{ file.Error }}</td>
-                      </tr>
-                      <tr v-if="file.Missing">
-                        <td>
-                          <translate>Missing</translate>
-                        </td>
-                        <td>
-                          <translate>Yes</translate>
-                        </td>
-                      </tr>
-                      <tr>
-                        <td>
-                          <translate>Added</translate>
-                        </td>
-                        <td>{{ formatTime(file.CreatedAt) }}
-                          <translate>in</translate>
-                          {{ Math.round(file.CreatedIn / 1000000) | number('0,0') }} ms
-                        </td>
-                      </tr>
-                      <tr v-if="file.UpdatedIn">
-                        <td>
-                          <translate>Updated</translate>
-                        </td>
-                        <td>{{ formatTime(file.UpdatedAt) }}
-                          <translate>in</translate>
-                          {{ Math.round(file.UpdatedIn / 1000000) | number('0,0') }} ms
-                        </td>
-                      </tr>
-                      </tbody>
-                    </table>
-                  </div>
-                </v-flex>
-              </v-layout>
-            </v-container>
-          </v-card-text>
-        </v-card>
-      </v-expansion-panel-content>
+                          </td>
+                          <td>
+                            <translate>Yes</translate>
+                          </td>
+                        </tr>
+                        <tr v-if="file.Portrait">
+                          <td>
+                            <translate>Portrait</translate>
+                          </td>
+                          <td>
+                            <translate>Yes</translate>
+                          </td>
+                        </tr>
+                        <tr v-if="file.Projection">
+                          <td>
+                            <translate>Projection</translate>
+                          </td>
+                          <td>{{ file.Projection | capitalize }}</td>
+                        </tr>
+                        <tr v-if="file.AspectRatio">
+                          <td>
+                            <translate>Aspect Ratio</translate>
+                          </td>
+                          <td>{{ file.AspectRatio }}</td>
+                        </tr>
+                        <tr v-if="file.MainColor">
+                          <td>
+                            <translate>Main Color</translate>
+                          </td>
+                          <td>{{ file.MainColor | capitalize }}</td>
+                        </tr>
+                        <tr v-if="file.Type === 'jpg'">
+                          <td>
+                            <translate>Chroma</translate>
+                          </td>
+                          <td>{{ file.Chroma }} / 100</td>
+                        </tr>
+                        <tr v-if="file.Error">
+                          <td>
+                            <translate>Error</translate>
+                          </td>
+                          <td>{{ file.Error }}</td>
+                        </tr>
+                        <tr v-if="file.Missing">
+                          <td>
+                            <translate>Missing</translate>
+                          </td>
+                          <td>
+                            <translate>Yes</translate>
+                          </td>
+                        </tr>
+                        <tr>
+                          <td>
+                            <translate>Added</translate>
+                          </td>
+                          <td>{{ formatTime(file.CreatedAt) }}
+                            <translate>in</translate>
+                            {{ Math.round(file.CreatedIn / 1000000) | number('0,0') }} ms
+                          </td>
+                        </tr>
+                        <tr v-if="file.UpdatedIn">
+                          <td>
+                            <translate>Updated</translate>
+                          </td>
+                          <td>{{ formatTime(file.UpdatedAt) }}
+                            <translate>in</translate>
+                            {{ Math.round(file.UpdatedIn / 1000000) | number('0,0') }} ms
+                          </td>
+                        </tr>
+                        </tbody>
+                      </table>
+                    </div>
+                  </v-flex>
+                </v-layout>
+              </v-container>
+            </v-card-text>
+          </v-card>
+        </v-expansion-panel-content>
+      </template>
     </v-expansion-panel>
     <p-file-delete-dialog :show="deleteFile.dialog" @cancel="closeDeleteDialog"
                           @confirm="confirmDeleteFile"></p-file-delete-dialog>
diff --git a/internal/entity/file.go b/internal/entity/file.go
index 1913b105c..de67425fe 100644
--- a/internal/entity/file.go
+++ b/internal/entity/file.go
@@ -188,9 +188,18 @@ func (m *File) Delete(permanently bool) error {
 
 // Purge removes a file from the index by marking it as missing.
 func (m *File) Purge() error {
+	deletedAt := Timestamp()
 	m.FileMissing = true
 	m.FilePrimary = false
-	return Db().Unscoped().Exec("UPDATE files SET file_missing = 1, file_primary = 0 WHERE id = ?", m.ID).Error
+	m.DeletedAt = &deletedAt
+	return UnscopedDb().Exec("UPDATE files SET file_missing = 1, file_primary = 0, deleted_at = ? WHERE id = ?", &deletedAt, m.ID).Error
+}
+
+// Found restores a previously purged file.
+func (m *File) Found() error {
+	m.FileMissing = false
+	m.DeletedAt = nil
+	return UnscopedDb().Exec("UPDATE files SET file_missing = 0, deleted_at = NULL WHERE id = ?", m.ID).Error
 }
 
 // AllFilesMissing returns true, if all files for the photo of this file are missing.
diff --git a/internal/entity/photo.go b/internal/entity/photo.go
index 051570418..e15361c6f 100644
--- a/internal/entity/photo.go
+++ b/internal/entity/photo.go
@@ -1042,6 +1042,43 @@ func (m *Photo) PrimaryFile() (File, error) {
 	return PrimaryFile(m.PhotoUID)
 }
 
+// SetPrimary sets a new primary file.
+func (m *Photo) SetPrimary(fileUID string) error {
+	if m.PhotoUID == "" {
+		return fmt.Errorf("photo uid is empty")
+	}
+
+	var files []string
+
+	if fileUID != "" {
+		// Do nothing.
+	} else if err := Db().Model(File{}).
+		Where("photo_uid = ? AND file_missing = 0 AND file_type = 'jpg'", m.PhotoUID).
+		Order("file_width DESC").Limit(1).
+		Pluck("file_uid", &files).Error; err != nil {
+		return err
+	} else if len(files) == 0 {
+		return fmt.Errorf("photo %s has no jpegs", m.PhotoUID)
+	} else {
+		fileUID = files[0]
+	}
+
+	if fileUID == "" {
+		return fmt.Errorf("file uid is empty")
+	}
+
+	Db().Model(File{}).Where("photo_uid = ? AND file_uid <> ?", m.PhotoUID, fileUID).UpdateColumn("file_primary", false)
+
+	if err := Db().Model(File{}).Where("photo_uid = ? AND file_uid = ?", m.PhotoUID, fileUID).UpdateColumn("file_primary", true).Error; err != nil {
+		return err
+	} else if m.PhotoQuality < 0 {
+		m.PhotoQuality = 0
+		return m.UpdateQuality()
+	}
+
+	return nil
+}
+
 // MapKey returns a key referencing time and location for indexing.
 func (m *Photo) MapKey() string {
 	return MapKey(m.TakenAt, m.CellID)
diff --git a/internal/entity/photo_test.go b/internal/entity/photo_test.go
index ac52dcf0e..6233e09ad 100644
--- a/internal/entity/photo_test.go
+++ b/internal/entity/photo_test.go
@@ -910,3 +910,13 @@ func TestPhoto_Links(t *testing.T) {
 		assert.Equal(t, "7jxf3jfn2k", links[0].LinkToken)
 	})
 }
+
+func TestPhoto_SetPrimary(t *testing.T) {
+	t.Run("success", func(t *testing.T) {
+		m := PhotoFixtures.Get("19800101_000002_D640C559")
+
+		if err := m.SetPrimary(""); err != nil {
+			t.Fatal(err)
+		}
+	})
+}
diff --git a/internal/photoprism/purge.go b/internal/photoprism/purge.go
index b07d2dbb5..0a914dedf 100644
--- a/internal/photoprism/purge.go
+++ b/internal/photoprism/purge.go
@@ -89,7 +89,7 @@ func (w *Purge) Start(opt PurgeOptions) (purgedFiles map[string]bool, purgedPhot
 						continue
 					}
 
-					if err := file.Update("FileMissing", false); err != nil {
+					if err := file.Found(); err != nil {
 						log.Errorf("purge: %s", err)
 					} else {
 						log.Infof("purge: found %s", txt.Quote(file.FileName))
@@ -102,12 +102,23 @@ func (w *Purge) Start(opt PurgeOptions) (purgedFiles map[string]bool, purgedPhot
 					continue
 				}
 
+				wasPrimary := file.FilePrimary
+
 				if err := file.Purge(); err != nil {
 					log.Errorf("purge: %s", err)
-				} else {
-					w.files.Remove(file.FileName, file.FileRoot)
-					purgedFiles[fileName] = true
-					log.Infof("purge: flagged file %s as missing", txt.Quote(file.FileName))
+					continue
+				}
+
+				w.files.Remove(file.FileName, file.FileRoot)
+				purgedFiles[fileName] = true
+				log.Infof("purge: flagged file %s as missing", txt.Quote(file.FileName))
+
+				if !wasPrimary {
+					continue
+				}
+
+				if err := query.SetPhotoPrimary(file.PhotoUID, ""); err != nil {
+					log.Warnf("purge: %s (set new primary)", err)
 				}
 			}
 		}
@@ -228,6 +239,12 @@ func (w *Purge) Start(opt PurgeOptions) (purgedFiles map[string]bool, purgedPhot
 		time.Sleep(50 * time.Millisecond)
 	}
 
+	log.Info("purge: searching index for unassigned primary files")
+
+	if err := query.FixPrimaries(); err != nil {
+		log.Errorf("purge: %s (find unassigned primaries)", err.Error())
+	}
+
 	log.Info("purge: searching index for hidden media files")
 
 	if err := query.ResetPhotoQuality(); err != nil {
diff --git a/internal/query/files.go b/internal/query/files.go
index 49d24ff59..7197a59e1 100644
--- a/internal/query/files.go
+++ b/internal/query/files.go
@@ -103,6 +103,26 @@ func RenameFile(srcRoot, srcName, destRoot, destName string) error {
 
 // SetPhotoPrimary sets a new primary image file for a photo.
 func SetPhotoPrimary(photoUID, fileUID string) error {
+	if photoUID == "" {
+		return fmt.Errorf("photo uid is missing")
+	}
+
+	var files []string
+
+	if fileUID != "" {
+		// Do nothing.
+	} else if err := Db().Model(entity.File{}).Where("photo_uid = ? AND file_missing = 0 AND file_type = 'jpg'", photoUID).Order("file_width DESC").Limit(1).Pluck("file_uid", &files).Error; err != nil {
+		return err
+	} else if len(files) == 0 {
+		return fmt.Errorf("photo %s has no jpegs", photoUID)
+	} else {
+		fileUID = files[0]
+	}
+
+	if fileUID == "" {
+		return fmt.Errorf("file uid is missing")
+	}
+
 	Db().Model(entity.File{}).Where("photo_uid = ? AND file_uid <> ?", photoUID, fileUID).UpdateColumn("file_primary", false)
 	return Db().Model(entity.File{}).Where("photo_uid = ? AND file_uid = ?", photoUID, fileUID).UpdateColumn("file_primary", true).Error
 }
diff --git a/internal/query/files_test.go b/internal/query/files_test.go
index 193d8598c..056263532 100644
--- a/internal/query/files_test.go
+++ b/internal/query/files_test.go
@@ -165,15 +165,29 @@ func TestFileByHash(t *testing.T) {
 }
 
 func TestSetPhotoPrimary(t *testing.T) {
-	assert.Equal(t, false, entity.FileFixturesExampleXMP.FilePrimary)
+	t.Run("success", func(t *testing.T) {
+		assert.Equal(t, false, entity.FileFixturesExampleXMP.FilePrimary)
 
-	err := SetPhotoPrimary("pt9jtdre2lvl0yh7", "ft2es49whhbnlqdn")
+		err := SetPhotoPrimary("pt9jtdre2lvl0yh7", "ft2es49whhbnlqdn")
 
-	if err != nil {
-		t.Fatal(err)
-	}
-	//TODO How to assert
-	//assert.Equal(t, true, entity.FileFixturesExampleXMP.FilePrimary)
+		if err != nil {
+			t.Fatal(err)
+		}
+	})
+	t.Run("no_file_uid", func(t *testing.T) {
+		err := SetPhotoPrimary("pt9jtdre2lvl0yh7", "")
+
+		if err != nil {
+			t.Fatal(err)
+		}
+	})
+	t.Run("no_uid", func(t *testing.T) {
+		err := SetPhotoPrimary("", "")
+
+		if err == nil {
+			t.Fatal("error expected")
+		}
+	})
 }
 
 func TestSetFileError(t *testing.T) {
diff --git a/internal/query/photo.go b/internal/query/photo.go
index 9827c2634..b8a9781e6 100644
--- a/internal/query/photo.go
+++ b/internal/query/photo.go
@@ -129,3 +129,26 @@ func PhotosOrphaned() (photos entity.Photos, err error) {
 
 	return photos, err
 }
+
+// FixPrimaries tries to set a primary file for photos that have none.
+func FixPrimaries() error {
+	var photos entity.Photos
+
+	if err := UnscopedDb().
+		Raw(`SELECT * FROM photos WHERE 
+			deleted_at IS NULL 
+			AND id NOT IN (SELECT photo_id FROM files WHERE file_primary = true)`).
+		Find(&photos).Error; err != nil {
+		return err
+	}
+
+	for _, p := range photos {
+		log.Debugf("photo: finding new primary for %s", p.PhotoUID)
+
+		if err := p.SetPrimary(""); err != nil {
+			log.Warnf("photo: %s (set new primary)", err)
+		}
+	}
+
+	return nil
+}