Are they using 2 servers?
One for the Sage app server and the other as the RDSH? If so, is the sync working if ran on the app server?
What about trying to change the Compatibility Mode. I've had no problems running 2018 Adv out of the box on 2016, but just in case there's something else at play, that option might help.
Even with UAC being off, have they tried to "Run As Administrator"?
Is DEP turned off?
Did he run the installer from the sage UNC path? Or the physical sage wksetup? If the the former, are the share permissions set to full access?
finally, have they tried to do a full client uninstall, and reinstall if the client?
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George Khairallah
CTO | gotomyerp, LLC
george.k@gotomyerp.com | 877-888-5525
http://gotomyerp.com/------------------------------