There are certain demos I can't open. I get the error in the title. How can I fix it? I use nQuake.

how old are the demos? you might want to try mvdsv-fixer on them

The demos are from milton-reppie, yesterday. Think I know what the problem is: the complete address is too long. If I rename one of the demos to eg. 1.mvd, it works, or if I run the demo from qw/demos instead of qw/demos/damn-long-folder-name-for-a-specific-set-of-demos.

It's also happens when you have too many folders!