visual studio - Could not load file or assembly 'Microsoft.VisualStudio.Web.PageInspector.Loader

Question

Could not load file or assembly 'Microsoft.VisualStudio.Web.PageInspector.Loader, Version=1.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The module was expected to contain an assembly manifest.


Assembly manager loaded from:  C:WindowsMicrosoft.NETFrameworkv4.0.30319clr.dll
Running under executable  C:Program Files (x86)Common FilesMicrosoft SharedDevServer11.0WebDev.WebServer40.exe
--- A detailed error log follows. 

=== Pre-bind state information ===
LOG: User = TTLWIN2Kmiralp
LOG: DisplayName = Microsoft.VisualStudio.Web.PageInspector.Loader, Version=1.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
 (Fully-specified)
LOG: Appbase = file:///C:/SVN/temp/components/src/MasterpassProxy/src/Webservice/
LOG: Initial PrivatePath = C:SVNempcomponentssrcMasterpassProxysrcWebservicein
Calling assembly : (Unknown).
===
LOG: This bind starts in default load context.
LOG: Using application configuration file: C:SVNempcomponentssrcMasterpassProxysrcWebserviceweb.config
LOG: Using host configuration file: 
LOG: Using machine configuration file from C:WindowsMicrosoft.NETFrameworkv4.0.30319configmachine.config.
LOG: Post-policy reference: Microsoft.VisualStudio.Web.PageInspector.Loader, Version=1.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a

Answer 1

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:WindowsMicrosoft.NETFrameworkv4.0.30319Configweb.config
C:WindowsMicrosoft.NETFramework64v4.0.30319Configweb.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.