Error :Sorting and Paging Does not work Together

[redhat]

Hi,,

I am using Sigma Grid in our Asp.net application(C#) , it is working very well , Thanks ..
But some errors arise in this  condition , when I do sorting and use pagination ( both are predefined in our application) some errors arise in this line

LoadDataInfo ldi = JavaScriptConvert.DeserializeObject<LoadDataInfo>(lstr);

The error is

"Could not find member 'sortOrder' on object of type 'RuntimeType' "


Can u please suggest , where is the error and weather i have to add any thing extra in my application , to avoid this error

Thanks i advance