Hello Peter,
We tried to reproduce this design time exception in VS 2010 with RadMaskedDateTimeInput from Q2 2014 dlls but we did not succeed. Is it possible for you to isolate this in a runnable sample and send it to use in a separate support thread ? Which version of RadControls do you use ? Thank you in advance for your cooperation.
Regards,
Petar Mladenov
Telerik
Check out Telerik Analytics, the service which allows developers to discover app usage patterns, analyze user data, log exceptions, solve problems and profile application performance at run time.
Watch the videos and start improving your app based on facts, not hunches.