Hello Caroline,
Thank you for reaching out to us.
I apologize for the inconvenience.
This issue occurs because a default value for a variable has not been set. Once you set the default value, the issue should be resolved.
If you encounter the problem again after enabling the SCSS-to-CSS compiler, please let us know. Also, please note that the default and recommended behavior is to keep the SCSS-to-CSS compiler disabled.
If everything is working correctly now, we would appreciate it if you could mark the question as resolved by accepting one of our answers.
Thank you!