Arithmetic expression errors

[duck]

Hello,
I'm using rc 4.2.1 with max2020. For every new arithmetic expression I make I get a warning "Expression has errors..."
Even if its absolutely basic. The only ones that dont give me a warning are from previous projects. But even if I just copy the expression in the working file it will give me a warning.
I also tried a clean install with max2021 - same result.
Does anyone have a clue?

[Dragan]

Give us some expression example.

[duck]

return
XSectionLength;

for example

[duck]

problem solved! the problem was the expression was not linked yet.
but i think the warning is a bit misleading since it suggests something is wrong with the expression itself.