[Solved] Problem while filtering on my RadGrid

[Kem Arda]

When i wantto filter records on RadGrid, it throws the error : 

Microsoft JScript worktime error: Sys.WebForms.PageRequestManagerServerErrorException: No property or field 'AFieldName' exists in type 'EntityBase2'

I use a LLBLGEN datasource for my RadGrid.

What could cause that error?
Thanks...

[Kem Arda]

The problem is fixed when i set RetrieveDataTypeFromFirstItem  property of RadGrid to true.