HCW8001 Error: Unable to Determine the Tenant Routing Domain

Question

Encountering the error HCW8001 Unable to determine the Tenant Routing Domain while running the Hybrid Configuration Wizard (HCW).

Below are the relevant log entries observed during the process:

2025.03.05 15:09:31.633         10271 [Client=UX, Page=Configuring, fn=RunWorkflow, Workflow=Hybrid, Task=Initial, Phase=Configure, Thread=7] FINISH Time=2.0ms Results=PASSED (Configuration Complete)

2025.03.05 15:09:31.634         10270 [Client=UX, Page=Configuring, fn=RunWorkflow, Workflow=Hybrid, Task=Initial, Phase=ValidateConfiguration, Thread=7] START 

2025.03.05 15:09:31.635 *ERROR* 10271 [Client=UX, Page=Configuring, fn=RunWorkflow, Workflow=Hybrid, Task=Initial, Phase=ValidateConfiguration, Thread=7] FINISH Time=0.0ms Results=FAILED - (Validation Failure)

2025.03.05 15:09:31.635 *ERROR* 10273 [Client=UX, Page=Configuring, fn=RunWorkflow, Workflow=Hybrid, Task=Initial, Thread=7] FINISH Time=1606.0ms Results=FAILED

2025.03.05 15:09:31.636 *ERROR* 10268 [Client=UX, Page=Configuring, fn=RunWorkflow, Workflow=Hybrid, Thread=7] FINISH Time=1609.0ms Results=FAILED

2025.03.05 15:09:31.637 *ERROR* 10025 [Client=UX, Page=Configuring, fn=RunWorkflow, Thread=7] HCW8001 Unable to determine the Tenant Routing Domain

2025.03.05 15:09:31.637 *ERROR* 10025 [Client=UX, Page=Configuring, fn=RunWorkflow, Thread=7] HCW8092 One or more items failed validation during 'Hybrid Initialization' task.  Please see log file for details.

2025.03.05 15:09:31.638         10101 [Client=UX, Provider=OnPremises, Thread=7] Disposing Runspace.

Any guidance on resolving this issue would be appreciated.

Answer 1

Hello, @Jtek,

Welcome to the Microsoft Q&A platform!

According to your description, you encountered an issue with the Hybrid Configuration Wizard (HCW). The error HCW8001: Unable to determine the Tenant Routing Domain typically indicates a problem with the coexistence domain configuration.

Regarding HCW8001 Error, it can be inferred from previous similar cases that the probability is that there is a problem with the tenant's backend.

To resolve this issue more effectively, it is advisable for you to open an MS Support case. The support engineer can make some changes in the tenants to help you run HCW without error.

(Similar issue and resolution: HCW fails with HCW8001 – Unable to determine the tenant routing domain after Set-MsolDirSyncEnabled -EnableDirsync $true - Microsoft Q&A)

Should you need more help on this, you can feel free to post back. 

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If the answer is helpful, please click on “Accept answer” as it could help other members of the Microsoft Q&A community who have similar questions and are looking for solutions.

Thank you for your support and understanding.

Best Wishes,

Alex Zhang