I had create custom widget for Mendix version 4.7.2 which using needsEntityContext="true" in widget XML, found that during running in test project it cause an error when I tried to closed dataview form or trying to "Save" in dataview. By debug on the firebug its give me a clue that function applyContext is not perform correctly and cause and error for null context/dataview object. Here is my test project url: https://drive.google.com/open?id=0B6Ek2RgM8ytkZzc4MmJfRldrbEdwN29WV2hBTThKeWRFc1JN Thank you. Khunpon
Just modify the working widget and replace with my code and it work like magic.