HTTP 400 error when logging into a 7940 cisco phone

[joep789]

This error appears to be very common to many users thid morning. Trying to login cisco 7940 get HTTP 400 error message

[luis_cordova]

Hi @joep789 ,

Maybe this link can give you some help:

https://community.cisco.com/t5/ip-telephony-and-phones/cisco-ip-phone-7940-http-error-400-with-extension-mobility/td-p/3199594

Regards

[Mohammed al Baqari]

I am assuming that you are trying to login to extension mobility. Can you
verify that the URL is still correct, whether you are using http or https
and check RTMT if there are any alarms