M Code error

[TheGunners]

what error in this M Code

"Year_2", each if [Semester] = 1 then [Year_1] + 1 else [Year_1] - 1)

Please help me 

[TheGunners]

Please looking the error message below

How to fix this?

[Migasuke]

Hi @TheGunners ,

I would say your Year column is a Text data type, due that you can't add 1 as a number.
Solution is, change Year to number before this operation.