Looks like a certificate issue…did you follow the proper installtion steps? Can you please revalidate
https://docs.uipath.com/installation-and-upgrade/docs/orchestrator-about-installation
Hope this helps
Cheers
Do you see this error immediately upon navigating to the URL? Or is it after you enter username and password?
Can you check Event Viewer → Windows Logs → Application to see what error messages are being logged?