Not sure if this was covered in one of the fixes on 7.4.2, but on 7.4.1 I’ve found that a function embedded in a string concatenation in the Expression Editor for a template binding throws an NPE. This doesn’t seem to occur on non-template items.
Example for a “Text” property binding on a label:
trim(trim({TTPack.TU_Tbl::THK}) + "mm " + {TTPack.TU_Tbl::COLOR} + " " + {TTPack.TU_Tbl::COAT})
The embedded trim() function causes the error.