Hi,
We are not aware of such issue with RadEditor dialogs in UI for ASP.NET AJAX version 2015.3.111.
Here is a video showing a simple setup of RadEditor and ImageProperties dialog:
http://screencast.com/t/uG3kGAkkhA
What I suggest is to review
this article for configuring the web.config in your project and the
jQuery troubleshooting article.
If the issue still occurs please try to isolate your setup in as
simple runable project and send it back in an attachment that we could investigate on our side.
Best Regards,
Misho
Telerik by Progress
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