It's hard to say without a database trace / call stack. The error can come from either approval routing or the document access areas. Both uses person ID or person group, and here both are missing, for some reason. Some setup around invoicing and Docman might be missing, but I cannot say what it is. You need to get help seeing what database call produces that error.
Thank you for the reply !
Tracing is not always possible in a database due to controls around. If the reason for the error cannot be found functionally its obvious that you must debug.
It's much harder (more testing, more guessing) to find the reason functionality.
Debugging of course is easy provided that you are allowed in the database. Let me see what I can do, Thanks !
@Tharanga Ishara
Well, that helps even more. But just getting the database trace/log in the client would help. Can't you enable that?
I will check whether its possible, thanks !
If I manage to get it, will you be able to analyze it and help
?