Error Message on Export

I can’t find out how to manage this error message:
»syntax error at “caret” missing« im Feature mkmk in Zeile 20

It appears on a couple of fonts today …

Can check this tutorial https://www.glyphsapp.com/tutorials/troubleshooting-a-font-that-does-not-export
And send me the file?

Make sure the masters are anchor-compatible.

Only one Master. In each of three or four cases …

New glyphData in Version 728 fixed the problem. Thank you very much!

Is there a new version 728? I only see 726.

I send him a new build for testing.