Unknown segment with custom expression

Hello,

I have a question with 4 tables and I want to add a custom expression but I have an error:

My expression is simple:
case([Fixversion.Name] contains("CGH"),"Livraison continue",[Fixversion.Name] )
But i have an error:
image

My version is 0.49.13

Thanks for your help
Tania

check the contains formula, you're using it wrong: Custom expressions in the notebook editor