App fails when TEMP directory does not exist

My TEMP directory is pointing to a ram drive. After a reboot I didn't create it yet, forgot about it and started mp3tag and got this:

47

Not a big issue, but a better message would be nice. The error log file stays empty.

you redirected temp path of mp3tafg or %temp% ?
%temp% wow be bad idea... you will get in trouble with a lot of applications and windows itself.
In your case, you should create ramdrive automatically on early system startup to prevent problems.