I recently installed the latest version of ML from probably a 4 year old build and I've noticed that it saves quite a few files that have symbols .CR2, .JPG, and .MOV (Example: #-_}?$&[.CR2 - not an actual file name, just to show you what I mean)
I'm not sure if I'm losing photos as I can not remember what all I shot each day..
When attempting to open the files, it gives the invalid location pop-up as if you were trying to open a file that no longer exists or the drive has been removed.
I've just uninstalled the latest build and went back to the next oldest build and also manually reset my file numbering because I noticed the issue right after I rolled over IMG_9999. I'm not sure if that was the issue or if that was purely coincidental.
I'll make due with the older build for now, but hopefully I can update again someday!