Multiple “MP has rejected registration request from client_name because the Client Certificate has insufficient key length” Status Messages when upgrading Clients

Multiple “MP has rejected registration request from client_name because the Client Certificate has insufficient key length” Status Messages when upgrading Clients

I’m in the process of migrating my Clients from ConfigMgr 2007 to 2012.

However, I’ve noticed that I’m getting Status Messages with an ID of 5450 stating:

MP has rejected registration request from because the Client Certificate has insufficient key length.

Possible causes: The Client is earlier than Configuration Manager 2012 or did not generate or use a client certificate that meets the key length requirement.

This seems to impacting performance of my Site causing a backlog of messages on SQL and Replication delays.