Symptoms

When enabling "Automatic merging" through "Settings >> Branching model >> Enable automatic merging >> Save", the page shows:

HTTP Status 400 - 
 
description The request sent by the client was syntactically incorrect.

Cause

The Notifyr plugin was found to be causing this issue on a Bitbucket Server 2.10.1 instance . The customer has reported the issue to the vendor through their public issue tracker.

Resolution

The resolution is to disable the plugin.