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Troubleshooting and FAQ

New videos get Media's generic icon

The frame did not reach the site before the media item was saved, or the browser could not capture it. Open the browser console on the media form and choose the file again:

  • Client-side video thumbnail generation failed means the browser could not play or draw the file. Try a format it plays, such as H.264 MP4.
  • Failed to send thumbnail to server: 403 means the user cannot create or edit media of any type, or the CSRF token was rejected because the session changed. Reload the form.
  • Failed to send thumbnail to server: 400 means the server did not receive a JPEG image.
  • Failed to send thumbnail to server: 413 means the frame was over 10 MB.

On sites with more than one web server and no private file system, the frame may be stored on a different server from the one that saves the media item. Configure a private file system. See Installation.

The file name must also match: the frame is stored under the name of the file the editor chose, and is found again under the name Drupal saved. Transliteration, lowercasing, replaced spaces and a _0 suffix are handled; other renaming, for example by a module that adds a hash to file names, is not. Use the Regenerate Thumbnail tab for those files.

The Regenerate Thumbnail tab is missing

It appears only on media items whose source file is a video, for users who can edit the item. Images, documents and remote videos do not get it.

Regenerating fails for videos on another domain

When video files are served from a CDN or an S3 bucket, the browser only lets the page read the frame if that server sends an Access-Control-Allow-Origin header for the site. The form's player requests the video with CORS, so without the header the video does not load and the form asks you to wait for it, or shows Failed to generate thumbnail. The browser console reports the CORS error.

Thumbnails of private videos

They are saved in the private file system too, in private://client-video-thumbs/, so visitors need access to the media item's files to see them.

Does the server ever process the video?

No. The server stores the JPEG the browser sends and checks that it is a JPEG image of 10 MB or less. It never opens the video file.

Does it work with Media Thumbnails Video?

Both modules handle the same MIME types, and Media Thumbnails uses only one plugin per type. Install one of them.

Where did the old files in public://client-video-thumbs go?

Version 1.0.0 kept frames waiting for a media item in that public directory. The update media_thumbnails_client_video_post_update_delete_public_frames deletes those that no file entity uses. See Changelog and upgrading.