Can't use config param in a css asset

[McShelby]

Basically, it should work that way.

Are you sure, your context given to executeAsTemplate is what you think it is?

Otherwise, using the search

• Custom CSS throws: Type <nil> not supported in Resource transformations - #3 by LunaticMuch
• Error calling ExecuteAsTemplate: type <nil> not supported in Resource transformations

Check if your main.scss file exists at this location, is valid and not minified before.