I see an issue with drives other then C: Awfully it didnt show up very often, but often enough to be anoying. Saving a file several times in a session after more or less small changes, it gives me the message, that it could no longer overwrite the existign file. Save as with a different name to the same drive (same folder and other folder) gives the same error message. Save as to C: works. It looks like, that vst live has only read access to that drive, even it had write access before in the same session… With other software I can still write to that drive. This happens with internal and external drives except C: A restart of VST Live also solves this behavior till the next time it occurs.
VST Live does absolutely nothing special or different from other applications with files. Also never experienced this and writing to a lot of different drives, so there must be something about your environment. Often another app blocks a file, did you consider that? Try closing all other apps - really all, that includes browser, email etc.