How to create a video for a map?

Hmm. Was the video created in an editor or in Notepad? If the latter, I would also check the encoding, as the default encoding in Notepad may not work.
And check the paths again. The case sensitivity might play a role, so pay attention to that as well.

Update: If I change the file name in the path I'm indicating, add/remove a number/letter, the error doesn't occur, which means I've specified the path correctly.

Ah, that makes sense. Then it's probably the encoding...