can you check this out, it will explain the error for you :)
When you try to run a Microsoft ASP.NET 2.0 Web application that is
built on the Microsoft .NET Framework 2.0, you may receive an error
message that resembles one of the following error messages:
The base class includes the field 'MyControl_1', but its type
(MyControl) is not compatible with the type of control
Unable to cast object of type 'ASP.MyControl_ascx' to type
Circular file references are not allowed. Note: In these error
messages, MyControl is the name of the control that has caused the
error. MyNameSpace is the name of the namespace that this control is a
This is problem occurs because of the way in which ASP.NET 2.0 uses
the application references and the folder structure of the application
to compile the application. If the batch property of the
element in the web.config file for the application is set to true,
ASP.NET 2.0 compiles each folder in the application into a separate
assembly. In this scenario, a circular reference may occur.
Additionally, the compilation process may fail if either of the
following conditions is true:
•The application contains references to
•The application contains references to Web pages that are outside the
To resolve this problem, use one of the following methods:
Method 1: Modify the web.config file To modify the web.config file,
set the batch property of the element in the web.config
file for the application to false.
Note This method is recommended only for small applications. In large
production applications, when you set the batch property to false,
ASP.NET 2.0 compiles each page in the application into a separate
assembly. The individual page assemblies are then loaded at the next
available memory location. Additionally, the individual page
assemblies cannot be moved. This causes memory fragmentation.
Method 2: Reorder the folders in the application To avoid a circular
reference, reorder the folders in the application. To reorder these
folders, follow these steps:
1.Trace the references to the file and
from the file that is indicated by the error message.
2.Identify the circular reference.
3.To avoid the circular reference, put the referenced files together in the same folder.
without code and full error I and others cant really help!
hope it helps :)