Hi,
Sorry that you are seeing this issue with CodeMix.
Please note that CodeMix has reached end of life. No new releases will be made.
MyEclipse 2021 is the alternative which supports SASS/SCSS using the language server tech. I tested the @debug math.div(1, 2);
in MyEclipse 2021 and see no errors being reported. If possible, please install MyEclipse 2021 and evaluate it. We offer a free 30 day trial period.
Do let us know if you have any further questions.
–Swapna
Genuitec Support