Why did the frame just freeze?

Not quite sure what you expect from posting in this forum since you clearly don’t wish to share information which would help you.

For others who are reading, it’s best to submit as much information about your project, version, computer as possible to find a solution.

I wrote this tutorial, and now it’s outdated, and I can’t edit it, but there are no more “GPU Effects” with the current version of Shotcut.