Separate names with a comma.
This is a bit old but for anyone reading in the future. OP's error comes from not finding the method in the IGui interface. If you want to pop up...
I ended up using this one pretty successfully for what I wanted:...
Hello all, I am new to modding Empyrion. I have found this API tools library on GitHub: https://github.com/lostinplace/EmpyrionAPITools but I...