The reference servers for Model Context Protocol now refuse the 2.x Python library

On 18 August the fetch, git and time reference servers were changed to require the Python library at 1.29 or above and below 2.0, with a note in their documentation saying so. The 2.0 library shipped on 28 July, speaks the newer 28 July protocol revision while still serving older clients from the same server, and renamed the main server class. The 1.x line is now maintenance only — security and critical fixes.

What it means If your requirement is loose, a fresh install now pulls the 2.x library and the reference servers will not start on it. Pin explicitly before the next deploy.