I was tinkering in the Lab recently creating a new Trusted App through PowerShell, and at the “Enable-CsTopology” step it failed with a less-than-helpful error:

Enable-CsTopology : Command execution failed: "1" error categories reported in topology document.
At line:1 char:1
+ Enable-CsTopology
+ ~~~~~~~~~~~~~~~~~     + CategoryInfo          : InvalidOperation: (:) [Enable-CsTopology], DeploymentException     + FullyQualifiedErrorId : ProcessingFailed,Microsoft.Rtc.Management.Deployment.ActivateTopologyCmdlet

Unfortunately the log file didn’t add any value:

Error: An error occurred: "Microsoft.Rtc.Management.Deployment.DeploymentException" ""1" error categories reported in topology document."

Topology Builder to the Rescue!

I remembered that Topology Builder in Skype for Business now reports topology validation errors, so I ran it up and it immediately pointed me to the problem:

The following validation errors prevent this topology from being published. Please contact your support team.

	
All services in a pool must be of the same version.

Aha! Yes, my hybrid configuration here had resulted in the gateway being cross-referenced between sites. Now I understood the error it was quickly resolved. Thank you Topo Builder!

– Greig.