My company is in the process of moving to windows 10 and we have a handful of custom systems that have to be migrated. I was told to "Just make them work". One of those is a tool that was written in 2008 using all Telerik controls. This system was last updated in 2012 to run on windows 7. We have plans to move the functionality to a Universal App however, we have bigger fish to fry. here is a list of all the bugs we encountered so far:

Forms with tons of controls(170 in my case) take forever to Initialize(> 60 seconds) especially the RadDateTimePicker;

The UI freezes until the InitializeComponent method  completes. 

The forms occasionally throws timeout errors waiting on a Com Handoff for more then 60 seconds.

There is no databinding going on and there is no functionality tied to the initialization or loading of the forms in an MDI. Only Large forms have this problem.

Any form that executes the following code does not load:
this.RootElement.ApplyShapeToControl = true;