We had exactly the same error in single machine configuration.
- AGS 10.7.1 GeoEvent 10.7.1
When loading GeoEvent Manager page it was throwing the same error.
- ArcGIS GeoEvent Server is waiting for a connection to the Zookeeper. If this takes too long, contact System Administrator to make sure Gateway is properly running
After a bit of digging, we found that ArcGIS Server had an old certificate in it's keystore that was corrupted. ArcGIS Server Admin was still showing the old certificate entry which was returning "Error accessing certificate" when try to access the details (ArcGIS Server was set to use new valid CA certificate).
For some reason GeoEvent was still picking that one up, even though it should have had inherited ArcGIS Server's current valid certificate. Uninstalling, deleting all remaining folders under ProgramData\Esri and reinstalling GeoEvent did not help, GE was still picking up the old cert.
In our case, the resolution was (unsupported by Esri Tech Support):
- Access AGS keystore via Keystore explorer and remove corrupted old certificate from both locations Server\framework\etc\certificates and \arcgisserver\config-store\machines\<MACHINENAME>.
- Restart ArcGIS Server service, make sure that corrupted certificate is not listed in AGS Admin anymore.
- Uninstall GeoEvent, delete all remaining folders under ProgramData\Esri.
- Install GeoEvent. This should allow GE manager to load.
