One of the common reasons for a "Preview could not be generated" error are embedded (restricted) fonts in the file.

Files with embedded (restricted) fonts can be uploaded to backend of library but will not have a preview generated and will not show up in the library page (frontend).

Here are the options to address this:

1. Remove Restricted Fonts

The first solution is to remove the embedded (restricted) fonts from the file and upload it again. This will allow the file to be previewed and displayed on the library page.

2. Compress the File into a Zip File

If you do not want to remove the embedded (restricted) fonts from the file, you can also compress the file into a zip file and upload it to the backend of the library.

This will also allow the file to be previewed and displayed on the library page.

In order for the file to have a preview image, you will need to add a custom asset preview image. This can be done by following the steps outlined in our help center article on adding custom asset preview images.