The client should run well as normal user. It must be allowed to open a random UDP port on demand and listen to replies to the same port (which most usual hardware firewalls in NAT routers should do, but some additional software firewalls don't and do more harm than good).
But the launcher may need to be able to change executables in a program folder during updates (which the UAC would deny).
It may not be necessary to click "Repair" (because that starts a more intense check), just to start pslaunch.exe a few times (as administrator; but after another, not in parallel), to get updated rather reliably.