Error: The languagesystem DFLT

What does it mean?
Error: “The languagesystem DFLT dlft; statement must preceed all other language system statements.” in Class locl1 in line: 4


It means that, in File > Font Info > Features, the languagesystem DFLT dflt; statement must come before other language statements.

You probably have some outdated or imported code in a class called locl1. Possibly there are two languagesystem DFLT dflt; statements.

Thanks. I just deleted these entries and the fonts was exported just fine.