[X++] Wrong argument types in variable assignment

Quick reminder for common mistake:

Error Message

Sometimes it is the case that you modified a class and get an error when running the code afterwards in a different element or in a different method saying:
Wrong argument types in variable assignment

Solution

compile forward on most upper class in hierarchy
If you ensured you have no errors in your new code, most of the time the modified class is part of a hierarchy and the uppermost class needs to be compiled forward to solve this!