Affzo not working without mask abbreviation?

SOLVED

Hi

When I use the following line of code

Affzo [M]ITMDES2(NLIG)

I get the following exception

According to the documentation at https://online-help.sageerpx3.com/erp/12/staticpost/affzo/ this should be working

If I check the value of the field on that mask on that line using an Infbox, the field and the value is existing.

Also, if I set the screen abbreviation explicitely (like [M:SIH4]), it works as well.

Since the code is running on multiple different screens, setting the screen abbreviation explicitely is not an option.

Has anyone ever had the same behaviour?

I know, the chances that I'm getting a feedback on thi aren't very great, but it's friday and I am trying my luck ;-)