Recording issue: only Sound, vídeo not showing

Hi, this afternoon I did a meeting that I recorded. I tested recording before starting the meeting and it was ok, stored correctly in Dropbox. Now I did another test and it also worked. But the file for the 30 mins meeting only contains audio, not vídeo. For the tests before starting and now, I have 2 files correctly with àudio and vídeo, but the file with the 30 mins only contains audio, not vídeo. Is there any way to recover the vídeo? Is there any limitation on the time or file size? I have enough space in my Dropbox so this should not be the issue.
Thanks.