I haven't come across this myself however just a thought. Try updating the file save paths in the HKEY_CURRENT_USER/Software/Mirillis registry keys to the actual paths in your case (z:\users).

I had this same issue and here is how I have worked around it. There are 2 issues; 1. DEFAULT OUTPUT FOLDER PATHS: Action sets the output folder paths to the user who installs it e.g. "C:\Users\James\Videos\Action!\". This obviously creates issues for other users on the computer because they don't h...