Owntracks and Webcore

I am running Hubitat Elev on C-7. I have OwnTracks installed and running. I am trying to write a piston in Webcore to take advantage of OwnTracks but when I activate piston it comes back with an error:

An error has occurred while subscribing: groovy.lang.MissingMethodException: No signature of method: webcore-piston$_subscribeAll_closure76.call() is applicable for argument types: (java.lang.Boolean, groovy.json.internal.LazyMap, java.util.LinkedHashMap, java.util.LinkedHashMap) values: [true, [$:4, c:, co:changes_away_from, ct:t, fs:, lo:[a:presence, ...], ...], ...] Possible solutions: any(), any(), dump(), collect(), grep(), find()

Any ideas ? Thx W

Not sure here. Do you have Owntracks working in other pistons? Maybe giving us a trace from this one will help.

This is the first Piston that uses Owntracks.