Issue # 1 – Unable to create

It says “Unable to create” and “We were unable to create this agent due to an error. Try again.”
or
“Unable to update” and “We were unable to update this agent due to an error. Try again.”

More info:
The problem appears to be when copilot tries to save agent (POST to https://powervamg.us-il105.gateway.prod.island.powerapps.com/chatbotmanagement/tenants/…/environments/Default-…/minimalBots/api/…/publish – it returns 500 Internal Server Error).

Cause:
In my case the cause was my license was assigned a few hours before, so it seems like it takes some time for Microsoft to populate updates.
In the other case I troubleshooted it turned out user did not have a license assigned (license was removed), but “Create an agent” button was available.

Solution:
Ensure you have a license for Microsoft 365 copilot assigned and (ideally) wait 24 hours.
Microsoft: “If you recently purchased a license or started a free trial, it may take up to 24 hours for the license to take effect.”