try,
Shut down rack, if it’s running.
make a copy of “C:\Users\Vašek\Documents\Rack2” to "C:"
add a user environment variable to point to the new user dir.
Win+X → Settings → Advanced System Settings → Environment Variables
under “User variables for user …” → “New”
Start rack
If it works, you can delete C:\Users\Vašek\Documents\Rack2