Videos show no preview or won't play: how to fix it

When a video in firelet.media Gallery shows no thumbnail or won't play, Windows is almost always missing the decoder for its format. The gallery uses the video support built into Windows and ships no codecs of its own. Open the video, press the Microsoft Store button the viewer offers (HEVC, VP9 or AV1), then press Retry unrenderable files in the Library panel. On macOS and Linux, install FFmpeg.

Why a video shows no thumbnail or preview#

Phones and cameras record in several formats, and Windows only plays some of them out of the box. When it can't decode a file, the tile shows the file's extension and "no preview", hovering over it plays nothing, and the viewer explains what is missing instead of playing.

Two other causes look the same in the grid:

• The file is online only. A video in a OneDrive or Dropbox folder that isn't on this PC shows a cloud badge and no preview. See adding cloud folders for the Download previews for online-only files option.
• The file is damaged. An interrupted download or copy leaves a video Windows can't read at all. The viewer then says "This video could not be read".

Steps on Windows: install the extension, then Retry unrenderable files#

1. Double-click the video's tile to open it in the viewer. A panel names the problem, for example "This video uses HEVC (H.265)".
2. Press the Store button on that panel, such as Get HEVC Video Extensions. The Microsoft Store opens at the right page.
3. Install the extension from the Store.
4. Back in the gallery, press Alt+1 for Library and scroll to Previews.
5. Press Retry unrenderable files.

The gallery remembers files Windows could not render and skips them afterwards, so it doesn't stall on the same file every time. Retry unrenderable files clears that memory and tries them all again with the new extension. Then open the video once more.

Steps on macOS and Linux: install FFmpeg, then rescan#

The macOS and Linux builds are being finished and handle video differently. Videos play in the app's built-in browser engine, and the free FFmpeg tool is optional. Without it, videos are still listed with their name, size and date, but have no preview and no length. To add them:

1. Install FFmpeg, with Homebrew on a Mac or your distribution's package manager on Linux.
2. Close the gallery and start it again.
3. Press Scan in the toolbar. The next scan fills in each video's length, dimensions and preview.

Installing FFmpeg does not make HEVC, AVI or WMV play inside the app on those systems. For those, use Open in default app or Open externally, described below.

Old formats with no extension (DivX, Xvid)#

Windows no longer ships decoders for MPEG-4 Part 2 (DivX and Xvid) or for most older AVI and WMV files, and no Store extension adds them back. The viewer says so plainly: "This video uses an older format". You have two choices:

• Play it in another player with Open externally.
• Convert it to an H.264 MP4 with a video converter, save the copy in one of your library folders, and press Scan. H.264 plays everywhere, including in the gallery.

Still stuck: Open in default app#

The panel that explains a failed video always has an Open in default app button. The viewer's toolbar also has Open externally ("Open in whichever app Windows uses for this file type"), and in the grid you can right-click and choose Share and print → Open with… to pick a player.

If the viewer says "This video could not be read" or "This video could not be opened", and the format is H.264, the file itself is most likely incomplete or damaged. Copy it again from the camera, phone or original download. No codec will fix a broken file, so the viewer doesn't offer one.

Still no luck? Press the version chip in the title bar, choose Copy diagnostics, and paste the report into a message to support along with the video's format. For what plays well once it works, see playing videos and motion photos, and for the full list of formats, supported file formats.