Video attachment function from HTML editor upload spins with no error message if attachment is not allowed per glide.attachment.extensionsDescriptionThe client environment has movie type extensions (mp4,mov, etc) as prohibited extensions. However, when using the insert video page from the HTML editor, the page is not reporting this, and instead just sits with the upload in progress bar moving.Steps to Reproduce 1. Go to the glide.attachment.extensions property.2. Add 'doc' to value (this will cause all other extensions other than 'doc to be prohibited).3. Generate a new KB article.4. In the overview HTML editor select the insert Video Icon.5. In the popup window, Press Choose file and select a file type with a video extension (e.g. mp4 or mov).6. Press the Attach button. The window does not notify the file extension error and the upload progress bar permanently spins.Similar behavior occurs when using the video library option.WorkaroundThis problem has been fixed. If you are able to upgrade, review the Fixed In section to determine the latest version with a permanent fix your instance can be upgraded to. If a workaround is needed, go to the sys_embed_object list and deactivate video extensions the admin does not want supported.Related Problem: PRB1534690