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I am developing a .net page using Visual Studio 2013. When I run debug I get the following error:

The type 'ASP.masterpage_master' exists in both 'c:\Users\username\AppData\Local\Temp\Temporary ASP.NET Files\root\efd1c20e\f579b0cc\App_Web_masterpage.master.cdcab7d2.j5ldj9qt.dll' and 'c:\Users\username\AppData\Local\Temp\Temporary ASP.NET Files\root\efd1c20e\f579b0cc\App_Web_masterpage.master.cdcab7d2.ugxbjwp4.dll'

Some suggestions include adding extra items to the <compilation but="" it="" did="" not="" solve="" the="" problem.="" i="" have="" also="" closed="" visual="" studio="" and="" deleted="" temp="" files="" many="" mode="hold">
Any ideas of what else I can try?
PhilLenoir 19-Aug-14 14:18pm    
Your question was truncated, you might want to edit it? It looks like you have two libraries referenced containing the same class. You could remove the ,presumably redundant, reference from your project or change the name of your master page.
Member 10854933 19-Aug-14 15:23pm    
this page is not even using Master Page.Master. The Master file is called Master_RSO.master. When the page is ran on a test web server, it runs fine. Also the question was not truncated.

1 solution

You are having multiple assembly files in your project that the program can reference. Since you can use only one of them, you either need to copy/paste content of one to the other and delete the first one, or remove one of them.
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Member 10854933 19-Aug-14 15:19pm    
That is not the case. The pages run on the test server with no problem. On my machine the page will not compile.
Afzaal Ahmad Zeeshan 19-Aug-14 15:27pm    
Because they don't have multiple assemblies there, in your machine you're having multiple assemblies with same name at different (or same) locations.

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