IAX Peer rejected-Failure to pass ALC

I am getting this error:

IAX2 Peer ACL: Rejecting ‘192.168.1.253’ due to a failure to pass ACL ‘(BASELINE)’.

This is new and I didn’t make any changes.
Any idea what could be happening?

Thanks a lot.

Asterisk 11, FreePBX 12.

Did you recently run some updates on your server ?

Did the peer change IP addresses ?