Reposting this from Irony's issue tracker. Apparently this mod is not being parsed properly CWTools spits out a validation error even though the code works in the game.

The code

https://github.com/calniotrey/stellaris-list-extender/blob/c53cb802aedd90dd1b9e27c7003552f9c580bf67/common/scripted_effects/SLEX_scripted_effects.txt#L1184-L1186

And reported validation message: