I have copied the majority of the files to an external drive and deleted the corresponding ones from my iPad. Now, it has nine video files left. Under File Browser Pro, the file size are not shown. Only the length in seconds. These are the files that caused errors during the copying mentioned in the original post.
What will happen if I turn on iCloud now? With free storage on the iPad, will the original full version of these files alone with the rest of the files on iCloud get copied to my iPad or these problematic 9 files on my iPad will overwrite their full version on iCloud (assuming they are there)?
The goal is to move all the files from my iPad and iCoud to the external drive.
In FB Pro, when listing video files, if you hit the three vertical dots, the file name, creation date and size are displayed along with the menu of actions.