Installation of NET+OS v5.0 with GH 3.5 fails

I’m having trouble getting the upgrade to Net+OS 5.0 installed. Multi2000 v3.5c is installed and working fine. No licesing issues, etc. But the remainder of the installation, the Net+OS 5.0 installation fails. The following error is given: Multi2000 is not found on your system. Please go back to step 1 to install MULTI2000. How do I get the installation program to see that Multi2000 is installed?

There is a problem with the installation program. Use the executable in the attached zip file (ghs35patch.exe) so that you can properly install NET+Works.