Control File: field or variable is undefined
This error is an internal error as it should never happen to an end user to see it.
The happens when a process attempts to read a field or a variable that does not exist. The process is to first check whether the field or variable exists (is_defined() function) then to retrieve its content only if the field or variable exists.
If you are just an end user and got the packager to generate this error, you'll have to report it and we'll do our best to fix it quickly.