I renamed the the json file, a new 7 KB file has been created with default values on starting MM (the old one was 166 KB), but unfortunately the error remains.
I really like your theme and used it up to now with MM 5, but unfortunately with the recent MM version 5.0.4.2693 you get the following error on starting MM: --------------------------- Application Error --------------------------- Application throw an exception (LESS) Error evaluating function `if ...