Hi, this is my first time posting.
I have been using stata for sometime now and had no problem in running the following command from the Windows version (16 SE). However, when I tried to run it in the Mac version (16 SE), it returns the error. I am posting the command and the error message below. Anyone has any idea what is the reason for the error?

Code:
mixed outcome x i.g || group: c.x#i.g
(g is a categorical variable with four levels and x is a continuous variable.


Error Message:
3g#c: operator invalid
Again, exactly the same command will run without any problem in Windows version stata. The interaction in the single level naive OLS works just fine without any problem.
Any hint?

Thanks in advance.

Wen