"Open With" UI Element Documentation is broken - does the feature work?
Does the "Box Content Open With" feature work for anyone?
I see it as being broken in the developer documentation and I'm unable to get it working with my own app after following the documentation.
Have you tried posting this to the Box developer forums (https://community.box.com/t5/Platform-and-Development-Forum/bd-p/DeveloperForum) ? The community there may be able to help you figure out what's going wrong, or isolate the bug if any.