The Forms UserSyncClient handles sync'ing users/groups from Directory Server to Forms. It communicates with the Forms Routing Service and has a connection security mode (WinAuth/Transport; client certificate, etc.) just like other Forms components.

Previously, when you used the Forms Multi-Server Configuration Utility to update the security mode and endpoints of Forms components on the server, it didn't update the UserSyncClient.exe.config like it did the two web.config and RoutingEngineServiceHost.exe.config files (as applicable). If the UserSyncClient and Forms Routing Service security modes were mismatched, they failed to communicate.

The version of the utility released with 2025H1 now updates UserSyncClient.exe.config. It not handling that component before was an omission we corrected.