Had a quirky one recently where by a client was rebuilding a NVGRE gateway (as per this post) failed with the below warning.
Unable to set up Remote Access server to support multi-tenancy mode. (Remote Access server and the host are not configured for multi-tenancy.
Fix the issue in Remote Access server and retry the operation.).
Fix the issue in Remote Access server and retry the operation.
Having a quick look at my trusty NVGRE build checklist, found that the Cluster networks on the NVGRE VM Cluster we not set to allow client traffic on the External network.
Enabling this as per below and reran the gateway migrate job
After we re ran the migrate command, viola!
After this, the client was able to proceed without error