Unable to invoke method on NULL object reference: .....

What is going on here?

This warning (see first image below) is mostly connected to a corrupt "preference file". The "IDL System Error" is mostly the reason for this warning, see second image below.

Solution:

Delete the file "ramms_prefs.sav" mentioned in the "IDL System Error". Then RAMMS will start again. If you specified RAMMS preferences (working-, map- or ortho-directories), then you have to re-specify them.