Bug: Text editor turns red, onChanged() never called

Hi,

I'm using your json editor with a longer json file (about 600 lines). 

Display works fine (both text and tree view), but the editing only seems to work for the tree view.

When I change something in the text view the border turns red and also OnChanged() is never called.

Is there a line limit or some other issue? (the json itself is valid)

kind regards
Dr. Stefan Klose