"Invalid filename"

[Arkcon]

No. But once, while backing up my SE4 directory with Nero, it balked at a filename in the FQM folder. Something about the name being too long to meet standards or some such foo. Any any rate, it's possible the "folder within a folder to the 8th power" layout of your SE4 directory may be too much for Windows to handle, even if it could handle it before. Just a guess, really.