I am getting this warning on assembly references in a VS2012 Winforms application project. In this case the references are for Infragistics controls used by the app, which are located in the bin folder.
This issue has been addressed in the following link, but the answer ("set the Build Action" property) doesn't work because there is no Build Action property in VS2012 for referenced assemblies.
VS2005: Assembly '<assembly>' is incorrectly specified as a file.
What's the fix?
You probably refer to the wrong Assembly.
You need to "set the Build Action" for the Assembly which located in Bin folder, NOT from references.
Go to Solution Explorer > Expand the Bin folder, right click on the Assembly that give warning, and you should be able to set the Build Action
Again, it is not the assembly that located in the References panel but it is from Bin Folder
Have you tried removing the references, saving the solution and exiting Visual Studio - then re-opening the solution and re-adding the references?
The problem is almost certainly lurking in the project file (.csproj if this is a C# app) if you fancy opening it up in a text editor and having a look - might also help if you were to paste it here.
Alternatively, have you tried recreate the project from scratch? May be a quicker solution than trying to work out what's happened.
