It’s not restricted to a particular video file. I’ve been able to upload some videos fine but if I try another it comes up with that error.
One of the videos was a 15fps security camera video which I could perhaps understand wasn’t supported due to the non standard frame rate. Another was a 30fps video shot on an iPhone but it had that error. Another video at 30fps shot on iPhone worked fine.
I’m wondering if iOS is throwing up the error if the download/buffering of the video from iCloud is seen to be taking too long? Could it be that if Diarium isn’t given the complete file within a certain time it closes the gate and iOS throws up that error?