Can't get Disney Digital Files to play on Sansa View

I can’t get Disney Digital movie files (.wmv) to play on my Sansa View.  The first time I copied 2 Disney movies over in MSC mode, they worked.  Then, for reasons I won’t go into, I deleted everything and when I copied them back over, they wouldn’t work.  Eventually, I got the 2 movies back on the View in MSC mode and they worked, but I don’t really understand why.  Now I’ve got a 3rd Disney movie that I want on the Sansa View, but when I copy it over in MSC mode like I did the others, it doesn’t play!  I get the error message “Synchronize to continue your music subscription”.  What I discovered previously is (1) Syncing via Windows Media Player does NOT work on Disney Digital Files, and (2) I CANNOT convert the Disney Digital Files using the Sansa Media Converter (SMC).  I DID successfully convert videos I downloaded from YouTube using SMC, but they were converted to mp4 format.  The two Disney movies I previously copied on my Sansa View and that DO work, were merely copied and pasted onto the player in their native wmv format.  Is everything supposed to be in mp4 format and not wmv?  If so, why and how could the first two wmv Disney movies play fine but the subsequent movie not?

Also, sometimes when I plug the player into my computer it comes up listed as a device in Windows under Computer, even though it is still in MSC mode and normally comes up as a drive letter. When it does that, I have to unplug it from the computer, go into settings and select MSC mode again (even though it is IN MSC mode), shut the View off, then plug it back into my computer.