IIUC wM is the consumer of CRM WS and accordingly you must have created WSD connector. Make sure you pass the right credentials for Authentication to take place. As per the error I see if it failing with some Kerberos Authentication directly contact the team and work them.
Also see if you have to do some Kerberos settings on IS, for more details you can refer IS Administration Guide.
Then I guess there is some setting missing on Soap UI. Did you check if there is any settings for Kerberos. Kindly share details if you are able to get it fixed.
I got Kerberos related error while connecting to JDBC adapters when i updated my DB password.
One reason could be CRM updated some configuration at their end because of which password got changed or something.
Basically you need to check with CRM team if they are able to access the WSDL and Execute it.
However, Cross check if you are passing valid credentials.