v4 does not run

Have recently upgraded from v3 to v4. Have noted that v4 will not run after I use my utilities program (V-com fix-it). If I try to run N-track V4 it starts to load and then comes up with a message that it is looking for a temp. file. The only way I can use it is to re-install. This didn’t happen with v3. It’s real weird.