Most probably the culture of the project is not set correctly - please note that the culture on the client side should be equal to the culture on the server - that way the grid will send the data in format that will be understand by the Default MVC Model binder. I would suggest to check the Grid Globalization demo which shows example of how to correctly setup your project to have equal culture on both the client and the server. You can find this demo in the offline examples which comes with KendoUI for ASP.NET MVC installation.
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