Hi there,
Sorry that Photoshop 2021 is stuck at loading videos and reading the video format.
What is your computer's operating system and exact version of Photoshop in use? (latest is 22.0.1)
Does the problem occurs with all the videos and video formats?
Checkout the suggestions offered in this similar discussion and see if that helps: https://community.adobe.com/t5/photoshop/photoshop-cc-render-video-stuck-at-initializing-video-expor...
If that does not help, would you mind restoring the preferences for Photoshop? See this article for reference: https://t.co/ulJI7cGn1G You may want to backup your settings beforehand: https://t.co/4dX7gkr36D
Thanks,
Akash