I have error in Rad system when republish

Following error is coming in my log
i can’t understand this error
kidly guide me

Message = Object reference not set to an instance of an object.
Data = System.Collections.ListDictionaryInternal
InnerException =
TargetSite = Boolean get_PrimaryKey()
StackTrace = at RadSystems.ActionFormField.get_PrimaryKey()
at RadSystems.GeneratePageController.GenerateFormPageControllerCode()
at RadSystems.GeneratePageController.GeneratePageCode()
HelpLink =
Source = RadSystems
HResult = -2147467261

What was the last configuration you did before you got the message or encountered the error?