License activation fails with "Invalid key: This key does not match this TeamCity instance" error

Symptoms

TeamCity Enterprise license activation fails with Invalid key: This key does not match this TeamCity instance error.

Cause

The license is activated on another TeamCity Server. A single license can only be used on a single running TeamCity server at any given time.

Resolution

• If moving the license to another server is required, deactivate it on the old server and then reactivate it on the new one. The documentation provides instructions: Manage TeamCity Licenses.
• If it is a separate TeamCity Server installation, a separate license is required. A trial (limited-time) license can be used to run a server for testing purposes.