While upgrading UIM server from 8.51 to 9.0.2 it fails with the following error in installation log.
ERROR impl.UIMServerUpgradePreparationPanel$UpgradePreparationSwingWorkerThread:doInBackground:278 [SwingWorker-pool-1-thread-2] - Exception caught during validation checks.
(2) communication error, Failed to communicate with UIM Server instance for upgrade.
Reinsert administrator password and if error persists an uninstall and re-install of the product is required.: Failed to log into UIMServer at host 'xxx.xxx.xxx.xxx' after '5' attempts.
Disabling Local IP Validation on primary hub will solve the issue.
1.open controller probe GUI from UIM primary hub robot
2.go to Setup->IP
3.uncheck Local IP Validation