Hi ,
we are having some issues...while upgrading to 2017 version from older version.Mainly it's related UI.Some pages rad window is not opening...some pages extra scroll bar is coming...some pages...colour is getting darker...some pages..grid view boarder is extended..some pages...calendar popup direction is changed to bottomright instead of bottomleft.....in some pages..extra boarder is coming in header...it seems like having not properly upgraded .may be some reference and compatability issue...we have followed this link to upgrade....: http://blogs.telerik.com/aspnet-ajax/posts/12-12-21/upgrade-the-version-of-your-telerik-asp.net-controls-in-6-easy-steps.
Please guide us in this regards.