Umberto,
I've run check disk to determine hard drive health and system file checker to check for erroneous files. I've also disabled Windows Defender AND McAfee entirely and still getting the same error.
You may be able to send me a separate link to download gsx_p3d4_setup2-1.bin to see if this is the culprit since the hash didn't match in the checksum.If this is one of the first files that install into the system, this file could be the culprit, which I don't believe the issue is on my system but possibly the framework. Basically, if it is not on your servers, it could be somewhere in the transfer process. Between both Win 7 and Win10 systems I had, I've always had problems downloading updates from the FSDT live update or your servers here in Korea. Every update I've done with GSX always resulted in me having to uninstall and reinstall the program.