Hello Umberto,
This is my first post on your Forums and I also want to add my name to the list of people with problems since the update. I just spent two days on this, installing, reinstalling, checking .net updates, ensuring Windows Defender is not interfering with the GSX install, trying different SSD’s and so on. I used IObit Uninstaller and CCleaner to remove all traces of previous installs then installed again, and again from your site. I have P3Dv4.5 only on my PC and a number of other Add-Ons, which all work perfectly.
Before the updates my install was on C:/GSX and it worked well. However, since the update on my system your programme just does not want to work properly in any location other than C:/Program Files (x86). A location I am not happy about but at least the programme is now running. Yes, I have Windows Defender configured correctly with relevant Exclusions.
Hopefully, as developer, you will be able to provide us all with some idea of a solution in the near future.
Thanks,
Roger