Hello Peter,
Thank you for sharing your feedback.
We have actually already introduced a change in our source code, with regards to this exception. It is available in our Latest Internal Build. Please, give it a try and let us know how it goes.
Note, that the item is currently in testing and that is why its status is "In Development". When the testing is complete, the status will be changed to "Completed".
Regards,
Vladimir Stoyanov
Progress Telerik