RG1000 Error: Unknown build error

Question

C: \ Program Files \ MSBuild \ Microsoft \ Silverlight for phone \ v4.0 \ Microsoft.Silverlight.Common.targets (625.5): RG1000 error: Unknown build error: "An item with the same key has already been added. '

Done building project "FileName.csproj" - FAULT.

Build failed.

Get this error when I try to create soln.

Answer 1

Yesterday we faced the same problem. This happened after we merged the two branches in our TFS, so we looked at the project file. The same image was added twice to the project file. If you open this XML editor, you can look at part of it:

<ItemGroup> <Resource Include="Assets\Images\icon.png"> <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory> </Resource> </ItemGroup> 

Removing duplicate parts solves our problem, but it is really difficult to find such duplicates. Perhaps there is a more user-friendly option that I have not yet found.

Loans for this blog post , which has done a lot to solve the problem. In my search over the Internet, I also found a bug report . Maybe it's worth a look at this.

It seems that there are many possibilities to run this error. See the following questions here about stack overflow:

• C #: an element with the same key is already added when compiling an expression
• VS2010 "An item with the same key has already been added
• Visual Studio Error: An item with the same key has already been added.