opening file from downloaded email attachment

I've just had a weird experience with trying to open files that I downloaded from attachments to email.

I had students in my college course use MuseScore .9.5 all last year. They would send their assignments to me via email attachment. We had no trouble.

We just started up our new semester and the 60 students I have in two sections of this course were sending me their first assignments, this year using .9.6.1 (.9.6.2 wasn't available when I first distributed the program). None of their files would open. MuseScore crashed in .9.6.1. I then changed to .9.6.2 and it didn't crash, but nothing appeared.

Files copied/pasted into a network drive worked fine. Clearly something was going on in the email transmission. This had our Director of Computing and Network Services completely puzzled for a couple days. He finally realized that the compressed MuseScore format (the default) was exactly like a .zip file and could be extracted (he used 7-zip). When he did that he discovered the meta data and further realized that files with capitalized extension (.MSCZ) wouldn't open. For some reason they still don't know for sure, the emailed attachments had capilized extensions. Renaming the file with lower-case extension (.mscz) corrects the opening problem. Here's what he communicated to me:

"If the extension is .mscz it opens fine. If it's .MSCZ it doesn't work. We think the difference is that the uppercase one comes across if file extensions are hidden on the PC. I'm actually not sure what causes one behavior or the other. Specifically, the case of the filename has to match the case of the filename found in the "container.xml" file inside the archive. At any rate, I'm guessing it used to be case insensitive, and they broke something in the code, and that's why you're seeing the problem now. "

Weird, right? Has anyone else seen this problem, or might just be our Novel GroupWise email client?

Norman Lowrey