System.Net.Http Error After Visual Studio 15.8.1 (2017) Update

Today we started getting an error from three web applications.  Two were web services and one was an ASP.NET MVC website.  The error was:

Could not load file or assembly ‘System.Net.Http, Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a’ or one of its dependencies. The located assembly’s manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

The error was occurring on this standard line in the global.asax file:


Looking at the trace statements on the error page, there was a mention of a binding redirect, which I recall seeing in the web.config of the site.  That section in the web config looked like:

    <assemblybinding xmlns="urn:schemas-microsoft-com:asm.v1">
        <assemblyidentity culture="neutral" publickeytoken="b03f5f7f11d50a3a" name="System.Net.Http">
          <bindingredirect newversion="" oldversion="">

This config block had been in place since December, 2015.  The block seems to have been added by a NuGet package at the same time, possibly with a Framework version upgrade.

However it originally ended up there, removing the config block allowed the sites to launch again.  It’s unknown why this started happening after a Visual Studio upgrade.

Editing SharePoint Pages Using Visual Studio And WebDAV

I blog in a few different places.  I have my personal blog, my professional blog, and I maintain a blog at work to inform and educate co-workers.  At work, the blog is hosted on the company’s SharePoint server, which is fine.  I am still able to use Windows Live Writer and with it, the Insert Code plug-in.  My other two blogs use WordPress.

The Insert Code plug-in is invaluable to me because it does nice color coding of the text.  As part of that feature, it inserts a CSS style block into your post.  SharePoint doesn’t play well with this.  It tries to, but fails.  The intent is good.  SharePoint wraps your whole post in a div and gives it a class with a random name, then it rewrites the CSS styles so the classes will be scoped to only that containing div class.  Pretty smart way of encapsulating the styles.

Unfortunately, it fails on two points.  First, the containing div’s class is not like class=”123456789abcd”, it always precedes the class name with “ExternalClass”, so you get class=”ExternalClass123456789abcd”.  The rewritten CSS does not have any mention of “ExternalClass”.

The second mistake is in the rewritten CSS.  Your post will have a style block rewritten similar to:

123456789abcd h1 {color: red;}
123456789abcd h3 {color: green;}
123456789abcd .bold {font-weight: bold;}

Do you see the problem?  The class is 123456789abcd on the div (actually ExternalClass123456789abcd), but the stylesheet doesn’t scope it to that class.  Those are html tags it’s defining.  The stylesheet is looking for html tags of <123456789abcd>.

So, what can you do about this?  My solution was to put the stylesheet right in the template page so all the posts will be able to use those classes – that’s why I created this post.  The problem is, I couldn’t find anything in the SharePoint control panel to add a custom stylesheet (unlike WordPress, right?).  There was an option to edit the page using SharePoint Designer, so I installed Designer, only to find out the administrator didn’t allow editing using Designer. 

Other places on the Internet suggested adding a Content Editor web part and put the style sheet in there.  I tried it half-heartedly and gave up because it seemed way too “hack-y”.  But while doing so, it reminded me of something I used to know about SharePoint, that you could browse the site’s files using WebDav (assuming you had permissions).

So, what I did was map a network drive (a command found in many places in Windows Explorer) and gave it the URL of my SharePoint site.  Right away, I got an Explorer window with the template files.  I edited Default.aspx and Post.aspx and added my stylesheet.  The formatting was immediately applied.  Then I edited all my previous posts and removed my inline style code blocks to save space and reduce complexity.  Everything works now.

Visual Studio 2015 + Silverlight In VB.NET

At work, I was the first to upgrade my machine to Windows 10 and Visual Studio 2015.  Opening our application’s solution, I started resolving little errors here and there.  One problem was not so simple and had a very obscure solution.

We have a small collection of Silverlight apps written in VB.NET.  With the upgrade to Visual Studio 2015, they would not compile.  The errors returned were:

Microsoft (R) Visual Basic Compiler version
Copyright (C) Microsoft Corporation. All rights reserved.

vbc : error BC30002: Type ‘Global.Microsoft.VisualBasic.ApplicationServices.ApplicationBase’ is not defined.
vbc : error BC30002: Type ‘Global.Microsoft.VisualBasic.Devices.Computer’ is not defined.
vbc : error BC30002: Type ‘Global.Microsoft.VisualBasic.MyServices.Internal.ContextValue’ is not defined.
vbc : error BC30002: Type ‘Global.Microsoft.VisualBasic.ApplicationServices.User’ is not defined.
vbc : error BC30002: Type ‘Global.System.ComponentModel.Design.HelpKeyword’ is not defined.

In the course of troubleshooting, I excluded everything from the project except the AssemblyInfo file and I still got the errors.  So I created a new Silverlight project, which built fine, and compared the Detailed compiler output.  The compiler line in the 2015-created project had a slightly different parameter (difference highlighted):


This clicked with me from my experience with building Silverlight apps for the Zune, where you had to exclude the My namespace that is created with VB.NET applications.  Look at the assemblies being referenced.  ApplicationServices.ApplicationBase (My.Application), Devices.Computer (My.Computer), ApplicationServices.User (My.User).

So, how do you get this extra compile setting?  It’s in the .vbproj – there’s no UI for it.  You’ll have to edit the vbproj file directly.

Unload the Silverlight project, right-click it, and choose Edit .vbproj.  Look for the node <NoStdLib>true</NoStdLib> (there will be one per project configuration) and after it, add: <MyType>Empty</MyType>.  This node is included with new Silverlight projects in VS2015.

Save and reload the project and the MyType flag will be included in the vbc command line, which will allow the Silverlight application to compile.

Of course, a lot of people will probably create a new Silverlight project and move all their code into it and be just as successful.  But, if you don’t want that hassle, or if you just want to know why (as I did), there’s the solution.

Azure Aftermath

After the mess with the Azure SDK reserving ports that conflicted with my development environment, and the fact that the SDK didn’t do anything for the automated publishing I was looking for, I decided to uninstall it.  Well, that wasn’t a good idea.  You could say it was “Azure disaster.”

First off, the uninstall of the multiple elements of the Azure SDK did not remove the NETSH entries for the Azure Storage Emulator. so those had to be manually removed. Then, I reopened VS 2013 and suddenly none of my web projects open, saying they are all incompatible with this version of Visual Studio.  I tried to create a new web application and got the useful error:


So now I can’t open or create any web applications in Visual Studio.  I decide I should reinstall the Azure SDK to put back what was taken away, although in my mind I realize this is a ridiculous concept.

I download the SDK and run it.  I then get this error from the installer:


Absolutely incredible.  This is like dealing with anti-psychotic medication.  “Whoa whoa whoa, you just can’t uninstall Pericyazine, that can cause a psychotic episode.”

Next thing to do is a Repair of the Visual Studio installation, which is going to be at least an hour…  And that has fixed the web project issue, so at least uninstalling the Azure SDK is recoverable.  You just need to make sure you manually get rid of the ACL entries with these statements (at an Administrator command prompt):

netsh http delete urlacl url=
netsh http delete urlacl url=
netsh http delete urlacl url=

Yes, I do believe when Windows 10 and VS 2015 come out, this work machine is due for a reformat.

IISExpress – Error description: Access is denied. (0x80070005)

Today, I spent my entire work day trying to find the solution to this error.

When I would launch a web project from Visual Studio, IIS Express would fail to load.  The error reported was:

Failed to register URL "http://localhost:10000/" for site "Portal3" application "/". Error description: Access is denied. (0x80070005)

I started down the obvious track of checking permissions.  IISExpress would operate just fine when run as Administrator, but not as my normal user.  I was an administrator on the local machine, so that didn’t make any sense.

The only thing I had done that morning was use Disk Cleanup to delete all my temp files and archived error reports.  I checked %temp%\iisexpress.  I checked my *.config files in Documents\IISExpress over and over.  I restored configs from backups.  I read many potential solutions, some as crazy as not being able to use a user name with “bg” in it.

I tried an older iteration of the web application.  It worked.  I tried other web projects in the solution.  They worked.  At this point, I was the only developer in my team who had a single web project that wouldn’t launch.

Then, late as usual, I finally remembered the Windows Event Viewer.  IISExpress was logging these two events:

Event ID: 2269: The worker process for app pool ‘Clr4IntegratedAppPool’, PID=’7536′, failed to initialize the http.sys communication when asked to start processing http requests and therefore will be considered ill by W3SVC and terminated.  The data field contains the error number.

EventID 2276: The worker process failed to initialize correctly and therefore could not be started.  The data is the error.

That lead me down a totally different troubleshooting path.  While doing so, I set up a new website in IIS on port 8085.  Oddly, my new websites and application pools didn’t refresh after being created, which led me to think there was even more wrong with my workstation.  An IISRESET resolved that problem and I was able to browse to the web project using IIS.

So IIS would work on port 8085 but IISExpress would not work on port 10000.  And IIS would work for any other project on seemingly any other port. 

In a comment on one of the web posts that I read, I saw this command:

netsh http add urlacl url=http://localhost:10000/ user=everyone

I’d only ever used NETSH maybe once or twice for some obscure reason, but the inclusion of “ACL” in the command was encouraging.  Amazingly, the command worked!  Although I was happy, I was also disappointed that I wouldn’t be able to see what the value was previously so I could find out the root cause.

So I ran:

netsh http show urlacl

And that displayed a bunch of entries that included these as well (User and SDDL changed):

Reserved URL            :
    User: Me 
        Listen: Yes
        Delegate: No
        SDDL: D:(A;;GX;;;S-1-5-21-)

Reserved URL            :
    User: Me
        Listen: Yes
        Delegate: No
        SDDL: D:(A;;GX;;;S-1-5-21-

Reserved URL            :
    User: Me
        Listen: Yes
        Delegate: No
        SDDL: D:(A;;GX;;;S-1-5-21-)

Where did these come from?  I ran netsh http delete urlacl url=http://localhost:10000/ and removed the entry and confirmed IISExpress stopped working.  Then I ran netsh http delete urlacl url= and IISExpress started working again.

Something had added ACL entries for ports 10000-10002 that were conflicting with my web project, which was trying to run on port 10000 using IISExpress.  How did they get there?  I looked in Add/Remove Programs to get a clue as to what could have added these entries.  Who’s to blame?  The Azure SDK.  Azure Storage Emulator uses ports 10000-10002 and creates reservations for them.  This was installed during my attempts at getting command-line Web Publishing to work.

I never would have known anything about this unless I had read the Azure SDK documentation.  The error message I was given said nothing about port conflicts.  nothing led me down that path at all.  And it’s entirely possible no one else would have this problem unless they were running IISExpress on port 10000.

But the important takeaway from this is that NETSH will allow you to create reservations for port numbers that may conflict with other applications.