diff --git a/manager/task_export.go b/manager/task_export.go
index b4d6f2ee7..cc5ed8409 100644
--- a/manager/task_export.go
+++ b/manager/task_export.go
@@ -19,6 +19,7 @@ type ExportTask struct {
 }
 
 func (t *ExportTask) Start(wg *sync.WaitGroup) {
+	defer wg.Done()
 	// @manager.total = Scene.count + Gallery.count + Performer.count + Studio.count
 
 	t.Mappings = &jsonschema.Mappings{}
@@ -36,8 +37,6 @@ func (t *ExportTask) Start(wg *sync.WaitGroup) {
 	}
 
 	t.ExportScrapedItems(ctx)
-
-	wg.Done()
 }
 
 func (t *ExportTask) ExportScenes(ctx context.Context) {
diff --git a/manager/task_generate_markers.go b/manager/task_generate_markers.go
index d9f8252c2..2f0b6a09f 100644
--- a/manager/task_generate_markers.go
+++ b/manager/task_generate_markers.go
@@ -16,18 +16,18 @@ type GenerateMarkersTask struct {
 }
 
 func (t *GenerateMarkersTask) Start(wg *sync.WaitGroup) {
+	defer wg.Done()
+
 	instance.Paths.Generated.EmptyTmpDir()
 	qb := models.NewSceneMarkerQueryBuilder()
 	sceneMarkers, _ := qb.FindBySceneID(t.Scene.ID, nil)
 	if len(sceneMarkers) == 0 {
-		wg.Done()
 		return
 	}
 
 	videoFile, err := ffmpeg.NewVideoFile(instance.Paths.FixedPaths.FFProbe, t.Scene.Path)
 	if err != nil {
 		logger.Errorf("error reading video file: %s", err.Error())
-		wg.Done()
 		return
 	}
 
@@ -74,6 +74,4 @@ func (t *GenerateMarkersTask) Start(wg *sync.WaitGroup) {
 			}
 		}
 	}
-
-	wg.Done()
 }
diff --git a/manager/task_generate_preview.go b/manager/task_generate_preview.go
index 778a6fced..30b81f187 100644
--- a/manager/task_generate_preview.go
+++ b/manager/task_generate_preview.go
@@ -13,39 +13,35 @@ type GeneratePreviewTask struct {
 }
 
 func (t *GeneratePreviewTask) Start(wg *sync.WaitGroup) {
+	defer wg.Done()
+
 	videoFilename := t.videoFilename()
 	imageFilename := t.imageFilename()
-	if t.doesPreviewExist(videoFilename, imageFilename) {
-		wg.Done()
+	if t.doesPreviewExist(t.Scene.Checksum) {
 		return
 	}
 
 	videoFile, err := ffmpeg.NewVideoFile(instance.Paths.FixedPaths.FFProbe, t.Scene.Path)
 	if err != nil {
 		logger.Errorf("error reading video file: %s", err.Error())
-		wg.Done()
 		return
 	}
 
 	generator, err := NewPreviewGenerator(*videoFile, videoFilename, imageFilename, instance.Paths.Generated.Screenshots)
 	if err != nil {
 		logger.Errorf("error creating preview generator: %s", err.Error())
-		wg.Done()
 		return
 	}
 
 	if err := generator.Generate(); err != nil {
 		logger.Errorf("error generating preview: %s", err.Error())
-		wg.Done()
 		return
 	}
-
-	wg.Done()
 }
 
-func (t *GeneratePreviewTask) doesPreviewExist(videoFilename string, imageFilename string) bool {
-	videoExists, _ := utils.FileExists(instance.Paths.Scene.GetStreamPreviewPath(videoFilename))
-	imageExists, _ := utils.FileExists(instance.Paths.Scene.GetStreamPreviewImagePath(imageFilename))
+func (t *GeneratePreviewTask) doesPreviewExist(sceneChecksum string) bool {
+	videoExists, _ := utils.FileExists(instance.Paths.Scene.GetStreamPreviewPath(sceneChecksum))
+	imageExists, _ := utils.FileExists(instance.Paths.Scene.GetStreamPreviewImagePath(sceneChecksum))
 	return videoExists && imageExists
 }
 
diff --git a/manager/task_generate_sprite.go b/manager/task_generate_sprite.go
index c0a8e2557..ea8a70b26 100644
--- a/manager/task_generate_sprite.go
+++ b/manager/task_generate_sprite.go
@@ -13,15 +13,15 @@ type GenerateSpriteTask struct {
 }
 
 func (t *GenerateSpriteTask) Start(wg *sync.WaitGroup) {
+	defer wg.Done()
+
 	if t.doesSpriteExist(t.Scene.Checksum) {
-		wg.Done()
 		return
 	}
 
 	videoFile, err := ffmpeg.NewVideoFile(instance.Paths.FixedPaths.FFProbe, t.Scene.Path)
 	if err != nil {
 		logger.Errorf("error reading video file: %s", err.Error())
-		wg.Done()
 		return
 	}
 
@@ -30,17 +30,13 @@ func (t *GenerateSpriteTask) Start(wg *sync.WaitGroup) {
 	generator, err := NewSpriteGenerator(*videoFile, imagePath, vttPath, 9, 9)
 	if err != nil {
 		logger.Errorf("error creating sprite generator: %s", err.Error())
-		wg.Done()
 		return
 	}
 
 	if err := generator.Generate(); err != nil {
 		logger.Errorf("error generating sprite: %s", err.Error())
-		wg.Done()
 		return
 	}
-
-	wg.Done()
 }
 
 func (t *GenerateSpriteTask) doesSpriteExist(sceneChecksum string) bool {
diff --git a/manager/task_import.go b/manager/task_import.go
index 97ff0b81c..7664de0c9 100644
--- a/manager/task_import.go
+++ b/manager/task_import.go
@@ -20,9 +20,12 @@ type ImportTask struct {
 }
 
 func (t *ImportTask) Start(wg *sync.WaitGroup) {
+	defer wg.Done()
+
 	t.Mappings, _ = instance.JSON.getMappings()
 	if t.Mappings == nil {
-		panic("missing mappings json")
+		logger.Error("missing mappings json")
+		return
 	}
 	scraped, _ := instance.JSON.getScraped()
 	if scraped == nil {
@@ -41,8 +44,6 @@ func (t *ImportTask) Start(wg *sync.WaitGroup) {
 
 	t.ImportScrapedItems(ctx)
 	t.ImportScenes(ctx)
-
-	wg.Done()
 }
 
 func (t *ImportTask) ImportPerformers(ctx context.Context) {
@@ -231,6 +232,7 @@ func (t *ImportTask) ImportTags(ctx context.Context) {
 	for i, mappingJSON := range t.Mappings.Scenes {
 		index := i + 1
 		if mappingJSON.Checksum == "" || mappingJSON.Path == "" {
+			_ = tx.Rollback()
 			logger.Warn("[tags] scene mapping without checksum or path: ", mappingJSON)
 			return
 		}
@@ -350,6 +352,7 @@ func (t *ImportTask) ImportScenes(ctx context.Context) {
 	for i, mappingJSON := range t.Mappings.Scenes {
 		index := i + 1
 		if mappingJSON.Checksum == "" || mappingJSON.Path == "" {
+			_ = tx.Rollback()
 			logger.Warn("[scenes] scene mapping without checksum or path: ", mappingJSON)
 			return
 		}
diff --git a/utils/file.go b/utils/file.go
index 0ffa5f52f..e2b0ad0da 100644
--- a/utils/file.go
+++ b/utils/file.go
@@ -37,7 +37,6 @@ func EnsureDir(path string) error {
 	return err
 }
 
-// TODO test
 func RemoveDir(path string) error {
 	return os.RemoveAll(path)
 }