All project references have yellow triangles every time solution is loaded

Question

All my project (from the same solution) references are marked with a yellow triangle. The projects are all set to the same .NET version (4.5.1). The error log says:

Answer 1

I had the same thing happen but didn't suspect the 24 warnings I was getting was related to this error: Error 1 Unable to locate the .Net framework aspnet_merge.exe tool on path '~\Photo Archive\Main\etc\tools'. You need to set the msbuild property 'AspnetMergeToolPath' to the folder containing this tool. ODOT.PhotoArchive.Web

Trying to set the MS build property led to a lot of research just to find out WHICH property to set. So, Agent Ransack to the rescue -- searched my drive for the most recent version of the tool and copied it to the directory Visual Studio was complaining about.

Rebuilt the project with the idea of clearing the error but then the 24 warnings also disappeared.

FYI -- this is an MVC project which will replace a classic asp project. This might be peculiar to MVC projects.

At any rate, there was a lot of chasing snipes before this was finally tried. So, where this is happening, try handling any errors no matter how remote the possibility is they're related to the issue.

Answer 2

Try switching to managed compatibility mode in VS2013
you can do that by going to tools->options..->General tab and check the Use managed compatibility mode

Answer 3

I had the same problem as you can see in this picture.

Its reason was the hidden folder. I had hidden the folder containing the project files. I got rid of this problem by unchecking the hidden attribute of the root folder containing the project files and restarting the visual studio. Check it once, you might have checked the folder to be hidden.

Answer 4

I had similar issues and it usually comes down to the Target Framework (Project>Properties>Application). I was working on a solution using .NET 4.6 and for some reason the default framework for new projects have a different target (in my case it was 4.5.2). So make sure you check all your project at the very least have the same target framework.

Answer 5

Do the following:

In vs choose: tools->options->resharper->options-> general-> click the clear caches button.

then close all your opened tabs and shut down vs2013.

finally, start vs2013 again.

Let me know if that worked for you.