coldfusion error $func null

I have Coldfusion 11 web application that all of a sudden is returning the following error message for certain CFC's.  Not sure what has triggered this error suddenly occurring as we had not put through any code changes.   I can't work out what I need to to do resolve the error.  Has anyone seen the following error $func.... null error before and can explain what it means and what best to check/do to resolve?

cfeway2ecfc2104167940$funcPROCESSPAYMENT null <br>The error occurred on line 310.

Thanks,

Sebastian.