Unfortunately from what we see here in the forum it seems to happen quite often that a Prime file gets corrupted and fails to load.
Sometimes people end up with a file consisting of all zero bytes and then there is nothing which could be recovered.
Most of the times files which get corrupt are files which included a lot of pictures and it may be possible to recover some of the pictures and Prime regions which were there. Most of the time there still will be a lot which got lost.
Whether anything can still be salvaged or not is, of course, impossible to tell from the image you provided.
The best option anyway sure is to use the most recent backup file and redo the work from there.
However, if this is the first time you've learned that you should always back up, then you're on your own because, as far as I know, PTC doesn't offer a repair service, and if you can't post the file here, you'll have to try to repair it yourself.
Prime files are essentially zipped directories containing XML files. You can rename (a copy of !!) the corrupted mcdx file to .zip and then try to repair the corrupted archive using an archiver such as WinRAR. The repaired file probably won't work, but it's worth a try (rename it to .mcdx and see if Prime is happy with it).
If the file still doesn't work, you could try to see if the log file provides any clues as to which part of the archive the problem is occurring in and then continue working from there. Usually the log file is of not much help, though.
You could also take a valid Prime file and copy the contents of the repaired file into it.
It's just a matter of experimenting and fiddling around to see if you can get it to work after all.
Good luck!
