Thumbnails Not Generating or Showing as Black Squares

Note: Some interface details and visuals in this article may differ from the latest version of Luminar for Desktop. To see the current interface, visit the Luminar for Desktop walkthrough.

🤔 Why This Happens

Image thumbnails are considered as previews of already edited images, as Luminar for Desktop uses cached data and indexing to display your photos quickly, specifically in thumbnails.

🛠️ How to fix it?

You can simply clear Luminar for Desktop's cache with one button. Follow these steps:

Windows

1. Open Luminar for Desktop

2. Go to File > Preferences.

3. Find the “Catalog cache size" section within the Preferences window.

4. Click "Clear cache".

macOS

1. Open Luminar for Desktop.

2. Go to Luminar for Desktop > Settings.

3. Find the “Catalog cache size" section within the Settings window.

4. Click "Clear cache".

After clearing the cache, there might be a short delay when viewing previews of already edited pictures as Luminar for Desktop rebuilds them. This is normal.

You don't need to do this every day, but consider it regularly to free up space and fix any black thumbnail issues.

❓Q&A Section

🤔 Why is clearing the cache that contains cached previews sometimes important or necessary? Clearing these folders forces Luminar for Desktop to rebuild data from scratch. This is important for:

• 🖼️ Fixing Display Errors: Resolves issues where thumbnails/previews are corrupted, missing, outdated, or don't match edits.

• ⚙️ Resolving Instability: Can fix freezes or sluggishness if the cached data or index files have become corrupted.

---

🧹 In which cases should I clear the preview cache on my device? Consider clearing them if you experience:

• 🔄 Thumbnails or previews showing incorrect content, artifacts, or failing to update.

• ❌ Missing thumbnails.

---

🛡️ Will clearing the folders with cached previews delete my photos or edits? No. Clearing the cache does not delete your original photos or your editing adjustments. These are stored safely elsewhere in your Catalog and on your hard drive. Luminar will simply regenerate the necessary preview data.

---

⚠️ Are there any downsides? Yes, temporarily:

• 🐢 Slower Initial Performance: Luminar for Desktop will need time to regenerate previews. Performance will return to normal gradually.

• ⏳ Regeneration Time: Depending on the size of your catalog, the regeneration process might take some ti