Visual-studio – Found conflicts between different versions of the same dependent assembly that could not be resolved error

I solved this problem by clearing Visual Studio Component Model Cache.

Just delete or rename this folder:

%LocalAppData%\Microsoft\VisualStudio\11.0\ComponentModelCache

or

%LocalAppData%\Microsoft\VPDExpress\11.0\ComponentModelCache

and restart Visual Studio.

The version of Visual Studio you have is specified by the number e.g.

Visual Studio 2012 is 11.0 (as shown above)

Visual Studio 2013 is 12.0

Visual Studio 2015 is 14.0

Visual Studio 2017 is 15.0

Visual Studio 2019 is 16.0

For those that don't know: %LocalAppData%\ is the same as C:\Users\{yourUsername}\AppData\Local

For those who have multiple versions of Visual Studio installed, e.g. 2012 and 2013, it might help to remove the ComponentModelCache for both versions before restarting Visual Studio, e.g. 11.0 and 12.0.

I just ran into the same problem, and the culprit was my uninstalling of Visual Studio Express 2012. It's possible that it might be any version of Visual Studio, as comments on this answer are indicating the issue still happens with Visual Studio 2019. My overall order of operations was:

• Installed Visual Studio Express 2012 (long time ago)
• Used Visual Studio Express 2012 happily for many months
• Installed Visual Studio 2013 Premium
• Used Visual Studio 2013 Premium happily for weeks
• Uninstalled Visual Studio Express 2012
• ERROR

I'm not 100% certain on the cause of it, or what combinations of Visual Studio versions would exhibit this behavior. But the solution for me was to edit the root web.config files in the framework directories:

C:\Windows\Microsoft.NET\Framework\v4.0.30319\Config\web.config
C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config\web.config

(For different framework versions you may have different folders.)

And remove the nodes:

<remove assembly="Microsoft.VisualStudio.Web.PageInspector.Loader, Version=1.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
<add assembly="Microsoft.VisualStudio.Web.PageInspector.Loader, Version=1.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />

Be careful not to remove any opening/closing parent nodes which are also on the same line(s) as these.

This resolved the issue for me.