Can you please try upgrading a copy
of your project to version 4.1 (you could first upgrade to 4.1 SP1 and then to 4.1 SP3 as the officially supported upgrade path is up to 2 versions back) and let us know if the problems persist. If yes, please enable service trace logging
for your project and try to reproduce the error so the reasons behind this exception are recorded. Then you can send over the generated file so we can examine it and get a better idea of what might be causing this issue.
All the best,
the Telerik team
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