In case your User Profile stops working (no reply from clients) please try the following:
1. Uninstall UPC
2. Delete all program folders related to UPC. Both the C:\UPCtools and C:\Program Files (x86)\EhlerTech\User Profile Center
– Backup the XML files from C:\UPCtools\USMT_x64_v10\ if you made any customizations
3. Delete the whole UPcentral registry folder. (HKEY_CURRENT_USER\Software\UPcentral)
4. Reboot and reinstall UPC. It will prompt to install UPC tools and approve license.
5. Put all the settings back into UPC again.