CS0433: The type ... exists in both ... and ...

Question

User260076833 posted

Hello,

I am repeatedly getting the following error. When I then reload the page, the error doesn't appear again.

I have cleaned and rebuilt the project without change.

Any hints?

Thanks
Magnus

Compilation Error

Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.

Compiler Error Message: CS0433: The type 'div_lbr_journal_cmp_journalform_ascx' exists in both 'App_Web_j51yddf3, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' and 'App_Web_pbysrn4j, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null'

Source Error:

Line 30: <Tabs> Line 31: <cmp:TabPage runat="server" ID="tab_Journal" Caption="Zeitschrift"> Line 32: <cmp:JournalForm ID="frm_Journal" runat="server" /> Line 33: </cmp:TabPage> Line 34:

Answer 1

User-707554951 posted

Hi  Yeoman

Cause: Two different assemblies referenced in your application contain the same namespace and type, which produces ambiguity. 

To resolve this error, use the alias feature of the /reference (C# Compiler Options) compiler option or do not reference one of your assemblies.

More information in  Compiler Error CS0433.

Related links:

https://stackoverflow.com/a/15772222

https://stackoverflow.com/a/371434

https://forums.asp.net/t/998851.aspx?CS0433+The+type+bleh+exists+in+two+autogenerated+DLLs

Best regards

Cathy

Answer 2

User-879727125 posted

There seem to be many possible causes and the official MSDN documentation of the error code CS0433 shows just the one possibility that Cathy provided. For me I had copied code that had the attribute CodeFile in the Page element but for the new project it should be CodeBehind. I have submitted a relevant update to the error code CS0433 documentation page. That probably is not relevant to this thread except if anyone in the future has this error then this might be relevant to them.