Hi,
It looks like I encountered a previous mentioned bug "Incorrect AutoSize dimensions under Edge with tables in the content" (https://feedback.telerik.com/Project/108/Feedback/Details/173027-incorrect-autosize-dimensions-under-edge-with-tables-in-the-content).
I have a RadWindow with AutoSize is true that opens correctly in Google Chrome, but not in Microsoft Edge.
I read the release history but I didn't find the fix for the bug explicitly mentioned there:
http://www.telerik.com/support/whats-new/aspnet-ajax/release-history
Regards,
Chris.