I am running RadScheduler in a DNN 4.9.0 module with HotFix Telerik.Web.UI_2008_3_1327_dev_hotfix . It was running fine and I made a couple of additions to my production site and ran into the following challenges:
Switched out RadMenu with PanelBar (PanelBar is working fine).
Added RadEditor (RadEditor is working fine).
Then I realized that all of the hours have disappeared from my RadScheduler. The appointment times are still listed but no hours are associated.