blocks|key|115543|text|我解决了我的问题。我卸载了项目并编辑了.csproj文件。我做了以下更改：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|115544|115545|<UseIISExpress>false</UseIISExpress>+to+true|unordered-list-item|offset|length|style|CODE|115546|Remove+<UseIIS>True</UseIIS>|115547|Remove+<IISUrl>http://localhost/MyWebApp</IISUrl>|115548|115549|然后我重新加载了项目。啊，真灵。实际上，它回滚到使用IIS+Express。|115550|entityMap^0|0|0|0|10|0|7|L|0|7|16|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|T|8|@]|9|@]|A|$]]|$1|C|3|D|5|E|7|U|8|@$F|V|G|W|H|I]]|9|@]|A|$]]|$1|J|3|K|5|E|7|X|8|@$F|Y|G|Z|H|I]]|9|@]|A|$]]|$1|L|3|M|5|E|7|10|8|@$F|11|G|12|H|I]]|9|@]|A|$]]|$1|N|3|-4|5|6|7|13|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|14|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|15|8|@]|9|@]|A|$]]]|R|$]]

I solved my problem. I unloaded the project and edited .csproj file. I did the following changes:

<ul>
<li><code>&lt;UseIISExpress&gt;false&lt;/UseIISExpress&gt;</code> to true</li>
<li>Remove <code>&lt;UseIIS&gt;True&lt;/UseIIS&gt;</code></li>
<li>Remove <code>&lt;IISUrl&gt;http://localhost/MyWebApp&lt;/IISUrl&gt;</code></li>
</ul>

Then I reloaded the project. It worked. Actually it rolled back to use IIS Express.

blocks|key|116238|text|同样的问题也发生在我的系统中，通过在管理员模式下运行Visual+Studio得到了解决。问题是IIS与ASP.NET项目具有相同的host%2Bport名称，并且没有管理员权限，Visual+Studio无法添加网站。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|116239|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

The same problem occurred at my system and got solved by running The Visual Studio in administrator mode. The issue was IIS having the same host+port name as ASP.NET project and without administrator rights Visual Studio was not able add the website.

blocks|key|2666766|text|在使用Visual+Studio+2015从IIS+Express切换到完整版IIS后，我遇到了此错误。当我以管理员身份运行Visual+Studio时，我能够加载项目。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2666767|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

I had this error after switching from IIS Express to full IIS with Visual Studio 2015.
I was able to load the project when I ran Visual Studio as Administrator.

blocks|key|118519|text|我在VS+2015中也遇到了类似的错误。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|118520|由于无法创建visual+c#+2015编译器，因此无法打开|118521|。“已添加具有相同密钥的”|blockquote|118522|118523|118524|我可以通过在Visual+Studio+2013中打开该解决方案，清除该解决方案，关闭visual+studio，然后在Visual+Studio+2015中打开相同的解决方案来解决此问题。|118525|我还注意到，在执行了这一系列事件之后，最初给出此错误的项目的csproj文件更新了它的ProjectExtensions元素并设置了<UseIIS>False</UseIIS>|offset|length|style|CODE|118526|下图显示了csproj在发生错误时和解决方法后的差异。|118527|​|118528|📷|atomic|118529|118530|请记住，在我使用此变通方法之前，我尝试手动更新该元素并将其设置为false，但这并不起作用。|118531|entityMap|0|IMAGE|mutability|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/7b8dd78bc7e05a273c3606722b8b85ac.png|imageAlt^0|0|0|0|0|0|0|1U|M|0|0|0|0|1|0|0|0|0^^$0|@$1|2|3|4|5|6|7|19|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|1A|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|1B|8|@]|9|@]|A|$]]|$1|G|3|-4|5|6|7|1C|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|1D|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|1E|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|1F|8|@$M|1G|N|1H|O|P]]|9|@]|A|$]]|$1|Q|3|R|5|6|7|1I|8|@]|9|@]|A|$]]|$1|S|3|T|5|6|7|1J|8|@]|9|@]|A|$]]|$1|U|3|V|5|W|7|1K|8|@]|9|@$M|1L|N|1M|1|1N]]|A|$]]|$1|X|3|T|5|6|7|1O|8|@]|9|@]|A|$]]|$1|Y|3|Z|5|6|7|1P|8|@]|9|@]|A|$]]|$1|10|3|-4|5|6|7|1Q|8|@]|9|@]|A|$]]]|11|$12|$5|13|14|15|A|$16|17|18|-4]]]]

I was getting a similar error in VS 2015. 

<blockquote>
 "could not be opened because the visual c# 2015 compiler could not be
 created." "with the same key has already been added"
</blockquote>

I was able to workaround the issue by opening the solution in Visual Studio 2013, Cleaning the solution, closing visual studio, then opening the same solution in Visual Studio 2015. 

I also noticed that after doing this sequence of events, the csproj file of the project that was initially giving this error updated its ProjectExtensions element and set <code>&lt;UseIIS&gt;False&lt;/UseIIS&gt;</code>

Image below of diff between csproj when error was occuring and after workaround. 

<a href="https://i.stack.imgur.com/NNcAb.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/NNcAb.png" alt="enter image description here"></a>

Keep in mind that before I used this workaround, I tried to update that element manually and set to false, but that did not work.

blocks|key|2878031|text|问题是应用程序已经配置为使用本地IIS而不是Express，并且它们可能是您无法加载应用程序的两个问题。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2878032|问题1.您的本地系统中没有安装IIS，在这种情况下，您必须安装IIS，或者必须打开.csproj文件并进行更改：|offset|length|style|BOLD|2878033|++<UseIISExpress>false</UseIISExpress>+to+true
++Remove+<UseIIS>True</UseIIS>
++Remove+<IISUrl>http://localhost</IISUrl>|code-block|syntax|javascript|2878034|IIS2.+Visual+studio无法访问，在这种情况下，只需在管理员模式下打开Visual+studio即可。|2878035|entityMap^0|0|0|4|15|7|0|0|N|Z|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@$D|S|E|T|F|G]|$D|U|E|V|F|G]]|9|@]|A|$]]|$1|H|3|I|5|J|7|W|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|X|8|@$D|Y|E|Z|F|G]]|9|@]|A|$]]|$1|O|3|-4|5|6|7|10|8|@]|9|@]|A|$]]]|P|$]]

The problem is the app has been configured to use local IIS instead of Express and their coud be two issues for which you are unable to load the app.

Issue 1. You don't have IIS installed in your local system, In this case you have to install IIS or have to open the .csproj file and do the changes:

<pre><code> &lt;UseIISExpress&gt;false&lt;/UseIISExpress&gt; to true
 Remove &lt;UseIIS&gt;True&lt;/UseIIS&gt;
 Remove &lt;IISUrl&gt;http://localhost&lt;/IISUrl&gt;
</code></pre>

Issue 2. Visual studio doesn't have access to IIS, in this case just open the Visual studio in administrator mode.

blocks|key|2666901|text|我也遇到过类似的问题，但上面提到的解决方案对我来说都不起作用。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2666902|但是，我是从visual+studio最近的解决方案列表中打开我的解决方案的。但是当我在资源管理器中双击打开解决方案文件时，项目加载正确。|2666903|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

I was facing similar issue but none of the mentioned solutions worked for me. 

However, I was opening my solution from within visual studio recent solutions list. But when I opened the solution file from explorer by double clicking on it, the project loaded correctly.

blocks|key|115528|text|当尚未在IIS中设置身份验证或尚未在IIS中设置网站(或虚拟目录)时，通常会发生这种情况。若要解决此问题，请打开IIS管理器。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|115529|115530|确保存在项目的网站或虚拟目录，并指向包含项目的bin文件夹的文件夹。|ordered-list-item|115531|打开身份验证并启用匿名Authentication.|115532|Click编辑当匿名身份验证为特定于selected.|115533|Select的用户时，请输入您的(domain\username).|115534|Open+Settings.|115535|Select凭据和|115536|授权规则。|115537|确保仅存在允许/所有用户。|115538|转到应用程序池->高级Windows身份并输入您的Windows凭据sure|115539|115540|这将打开网站，以便Visual+Studio可以加载您的项目。如果没有，请转到站点的高级设置并选择物理路径凭据。确保将其设置为直通身份验证。|115541|entityMap^0|0|0|0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|11|8|@]|9|@]|A|$]]|$1|C|3|D|5|E|7|12|8|@]|9|@]|A|$]]|$1|F|3|G|5|E|7|13|8|@]|9|@]|A|$]]|$1|H|3|I|5|E|7|14|8|@]|9|@]|A|$]]|$1|J|3|K|5|E|7|15|8|@]|9|@]|A|$]]|$1|L|3|M|5|E|7|16|8|@]|9|@]|A|$]]|$1|N|3|O|5|E|7|17|8|@]|9|@]|A|$]]|$1|P|3|Q|5|E|7|18|8|@]|9|@]|A|$]]|$1|R|3|S|5|E|7|19|8|@]|9|@]|A|$]]|$1|T|3|U|5|E|7|1A|8|@]|9|@]|A|$]]|$1|V|3|-4|5|6|7|1B|8|@]|9|@]|A|$]]|$1|W|3|X|5|6|7|1C|8|@]|9|@]|A|$]]|$1|Y|3|-4|5|6|7|1D|8|@]|9|@]|A|$]]]|Z|$]]

This often happens when authentication has not been setup in IIS or the website (or virtual directory) has not been setup in IIS. To fix this problem, open IIS manager.

<ol>
<li>Make sure a website or virtual directory exists for the project and points to the folder that contains the bin folder for your project.</li>
<li>Open Authentication and enable Anonymous Authentication.</li>
<li>Click Edit while Anonymous Authentication is selected.</li>
<li>Select Specific user, enter your Windows credentials (domain\username).</li>
<li>Open .NET Authorization Rules.</li>
<li>Make sure only Allow/All Users exists.</li>
<li>Go to Application Pools->Advanced Settings.</li>
<li>Select Identity and enter your Windows credentials (domain\username).</li>
</ol>

This should open up the website so Visual Studio can load your project. If not, go to Advanced Settings for you site and select Physical Path Credentials. Make sure that's set to pass-through authentication.

blocks|key|115574|text|我得到了这个错误。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|115575|我正在使用IIS-Express。我还有VS2015呢。|115576|在摆弄了.csproj文件之后……我能够让它正常工作。|115577|在将我当前的文件与TFS源代码控制中的文件进行比较后，唯一的区别就是这一行。|115578|以前，这条线是不存在的。在我的“工作”(在处理完它之后)文件中，我有|115579|<UseGlobalApplicationHostFile+/>|code-block|syntax|javascript|115580|同样，在导致错误的csproj中，我没有魔术行，但在工作的csproj中，我有它。|115581|下面是上下文中的上行代码。只对面包屑使用下面的内容，不要复制/粘贴所有内容。魔术线是从底部算起的3。|115582|<?xml+version="1.0"+encoding="utf-8"?>
<Project+ToolsVersion="4.0"+DefaultTargets="Build"+xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
++<Import+Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props"+Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')"+/>
++<PropertyGroup>
++++<Configuration+Condition="+'$(Configuration)'+==+''+">Debug</Configuration>
++++<Platform+Condition="+'$(Platform)'+==+''+">AnyCPU</Platform>
++++<ProductVersion>
++++</ProductVersion>
++++<SchemaVersion>2.0</SchemaVersion>
++++<ProjectGuid>{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}</ProjectGuid>
++++<ProjectTypeGuids>{E3E379DF-F4C6-4180-9B81-6769533ABE47};{349c5851-65df-11da-9384-00065b846f21};{fae04ec0-301f-11d3-bf4b-00c04f79efbc}</ProjectTypeGuids>
++++<OutputType>Library</OutputType>
++++<AppDesignerFolder>Properties</AppDesignerFolder>
++++<RootNamespace>MyRootNamespace</RootNamespace>
++++<AssemblyName>MyAssemblyName</AssemblyName>
++++<TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
++++<MvcBuildViews>false</MvcBuildViews>
++++<UseIISExpress>true</UseIISExpress>
++++<IISExpressSSLPort+/>
++++<IISExpressAnonymousAuthentication>enabled</IISExpressAnonymousAuthentication>
++++<IISExpressWindowsAuthentication>enabled</IISExpressWindowsAuthentication>
++++<IISExpressUseClassicPipelineMode>false</IISExpressUseClassicPipelineMode>
++++<SccProjectName>SAK</SccProjectName>
++++<SccLocalPath>SAK</SccLocalPath>
++++<SccAuxPath>SAK</SccAuxPath>
++++<SccProvider>SAK</SccProvider>
++++<UseGlobalApplicationHostFile+/>
++</PropertyGroup>
++<PropertyGroup+Condition="+'$(Configuration)%7C$(Platform)'+==+'Debug%7CAnyCPU'+">|115583|entityMap^0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|X|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|Y|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|Z|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|10|8|@]|9|@]|A|$]]|$1|J|3|K|5|L|7|11|8|@]|9|@]|A|$M|N]]|$1|O|3|P|5|6|7|12|8|@]|9|@]|A|$]]|$1|Q|3|R|5|6|7|13|8|@]|9|@]|A|$]]|$1|S|3|T|5|L|7|14|8|@]|9|@]|A|$M|N]]|$1|U|3|-4|5|6|7|15|8|@]|9|@]|A|$]]]|V|$]]

I was getting this error.

I am using IIS-Express. And I have VS2015.

After messing around with the .csproj file....I was able to get it to work.

After comparing my current file to what was in TFS source control, the only difference was this line.

Previously, this line did not exist. In my "working" (after messin' with it) file, I had

<pre><code>&lt;UseGlobalApplicationHostFile /&gt;
</code></pre>

Again, in the csproj that causes the error, I didn't have the magic line, but in the working csproj, I had it.

Below is the above line, in context. Only use the below for breadcrumbs, do not copy/paste all of it. The magic line is 3 from the bottom.

<pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
&lt;Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003"&gt;
 &lt;Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" /&gt;
 &lt;PropertyGroup&gt;
 &lt;Configuration Condition=" '$(Configuration)' == '' "&gt;Debug&lt;/Configuration&gt;
 &lt;Platform Condition=" '$(Platform)' == '' "&gt;AnyCPU&lt;/Platform&gt;
 &lt;ProductVersion&gt;
 &lt;/ProductVersion&gt;
 &lt;SchemaVersion&gt;2.0&lt;/SchemaVersion&gt;
 &lt;ProjectGuid&gt;{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}&lt;/ProjectGuid&gt;
 &lt;ProjectTypeGuids&gt;{E3E379DF-F4C6-4180-9B81-6769533ABE47};{349c5851-65df-11da-9384-00065b846f21};{fae04ec0-301f-11d3-bf4b-00c04f79efbc}&lt;/ProjectTypeGuids&gt;
 &lt;OutputType&gt;Library&lt;/OutputType&gt;
 &lt;AppDesignerFolder&gt;Properties&lt;/AppDesignerFolder&gt;
 &lt;RootNamespace&gt;MyRootNamespace&lt;/RootNamespace&gt;
 &lt;AssemblyName&gt;MyAssemblyName&lt;/AssemblyName&gt;
 &lt;TargetFrameworkVersion&gt;v4.5&lt;/TargetFrameworkVersion&gt;
 &lt;MvcBuildViews&gt;false&lt;/MvcBuildViews&gt;
 &lt;UseIISExpress&gt;true&lt;/UseIISExpress&gt;
 &lt;IISExpressSSLPort /&gt;
 &lt;IISExpressAnonymousAuthentication&gt;enabled&lt;/IISExpressAnonymousAuthentication&gt;
 &lt;IISExpressWindowsAuthentication&gt;enabled&lt;/IISExpressWindowsAuthentication&gt;
 &lt;IISExpressUseClassicPipelineMode&gt;false&lt;/IISExpressUseClassicPipelineMode&gt;
 &lt;SccProjectName&gt;SAK&lt;/SccProjectName&gt;
 &lt;SccLocalPath&gt;SAK&lt;/SccLocalPath&gt;
 &lt;SccAuxPath&gt;SAK&lt;/SccAuxPath&gt;
 &lt;SccProvider&gt;SAK&lt;/SccProvider&gt;
 &lt;UseGlobalApplicationHostFile /&gt;
 &lt;/PropertyGroup&gt;
 &lt;PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' "&gt;
</code></pre>

blocks|key|2666769|text|当我将我的WCF+REST服务从IISExpress迁移到本地主机时，我也遇到了同样的问题。因此，我所做的就是在记事本中打开.csproj文件并查找UseIISExpress，将其值从false更改为True。然后以管理员身份打开VS2015，它就可以工作了。好消息是，当我运行项目时，它仍然在我的本地主机上运行，而不是在IISExpress上运行。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2666770|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

I had the same problem when I moved my WCF REST service from IISExpress to localhost. So, what I did was I opened the .csproj file in Notepad and looked for UseIISExpress, changed its value from false to True.
Then opened VS2015 as administrator and it worked. The good thing is that when I run the project it is still running on my localhost not IISExpress.

blocks|key|2878147|text|我在Visual+Studio+2017的升级中遇到了这个问题。它已经修复，现在可以在更新的版本中使用。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2878148|您可以通过产品内通知或从https://www.visualstudio.com下载最新更新|offset|length|2878149|参考：Project+could+not+be+opened+because+the+Visual+C#+2017+compiler+could+not+be+created|2878150|entityMap|0|LINK|mutability|MUTABLE|url|https://www.visualstudio.com/|1|https://developercommunity.visualstudio.com/content/problem/209944/project-could-not-be-opened-because-the-visual-c-2.html^0|0|C|S|0|0|3|2C|1|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|S|8|@]|9|@$D|T|E|U|1|V]]|A|$]]|$1|F|3|G|5|6|7|W|8|@]|9|@$D|X|E|Y|1|Z]]|A|$]]|$1|H|3|-4|5|6|7|10|8|@]|9|@]|A|$]]]|I|$J|$5|K|L|M|A|$N|O]]|P|$5|K|L|M|A|$N|Q]]]]

I had this issue with an upgrade for Visual Studio 2017. It has been fixed and is now available in an updated release. 

You can download the latest update via the in-product notification or from <a href="https://www.visualstudio.com" rel="nofollow noreferrer">https://www.visualstudio.com</a> 

Ref:
<a href="https://developercommunity.visualstudio.com/content/problem/209944/project-could-not-be-opened-because-the-visual-c-2.html" rel="nofollow noreferrer">Project could not be opened because the Visual C# 2017 compiler could not be created</a>

blocks|key|2878202|text|我创建了一个新的Sln文件。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2878203|2878204|关闭解决方案。|2878205|打开主项目的project文件。将有问题的项目添加回新的Sln文件。|2878206|保存Sln文件，覆盖旧的有问题的文件。|2878207|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|L|8|@]|9|@]|A|$]]|$1|C|3|D|5|6|7|M|8|@]|9|@]|A|$]]|$1|E|3|F|5|6|7|N|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|P|8|@]|9|@]|A|$]]]|J|$]]

I created a new Sln file.

<hr>

Close the Solution.

Open the Project file of the main project. Add the offending projects back to the new Sln file.

Save the Sln file over the top of the old faulty one.

blocks|key|2878110|text|我也犯了同样的错误，这就解决了我的问题。在解决方案的根目录中，您应该会看到.vs/config/applicationhost.config。在此文件夹中，删除违规网站。我的是这样的：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2878111|++++++++<site+name="FrontEnd.Web"+id="2">
++++++++++++<application+path="/"+applicationPool="Clr4IntegratedAppPool">
++++++++++++++++<virtualDirectory+path="/"+physicalPath="C:\xxxxx\xxxxx\xxxxx\FrontEnd.Web"+/>
++++++++++++</application>
++++++++++++<bindings>
++++++++++++++++<binding+protocol="http"+bindingInformation="*:3391:localhost"+/>
++++++++++++</bindings>
++++++++</site>|code-block|syntax|javascript|2878112|我删除了此应用程序的整个站点标记，保存，然后右键单击my+solution+>+Add+>+Existing+Project，并将项目重新添加到解决方案中。|2878113|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

I had the same exact error, this is what solved my issue. In the root of your solution you should see a .vs/config/applicationhost.config. In this folder delete the offending site. Mine looked like this:

<pre><code> &lt;site name="FrontEnd.Web" id="2"&gt;
 &lt;application path="/" applicationPool="Clr4IntegratedAppPool"&gt;
 &lt;virtualDirectory path="/" physicalPath="C:\xxxxx\xxxxx\xxxxx\FrontEnd.Web" /&gt;
 &lt;/application&gt;
 &lt;bindings&gt;
 &lt;binding protocol="http" bindingInformation="*:3391:localhost" /&gt;
 &lt;/bindings&gt;
 &lt;/site&gt;
</code></pre>

I deleted the entire site tag for this application, saved and then, right-clicked my solution > Add > Existing Project and re-added the project to the solution.

I changed my ASP.NET web application to use Local IIS, instead of IIS Express. Now after re-opening the solution, the following error occurs while loading the application:
<blockquote>
error : Project 'Atlas2' could not be opened because the Visual C# 2015 compiler could not be created. 'Atlas2' is already part of the workspace.
error : Project 'Atlas2' could not be opened because the Visual C#
2015 compiler could not be created. An item with the same key has
already been added.
</blockquote>
Would someone please help me how I can reload the project?
I'm using Visual Studio Team Services (was TFS Online), if it helps.

An error occurs while loading my ASP.NET application after it is configured for IIS

Visual Studio

身份验证

编译器

Windows

我将我的ASP.NET web应用程序更改为使用Local IIS，而不是IIS Express。现在，在重新打开解决方案后，加载应用程序时出现以下错误：错误:无法打开项目'Atlas2‘，因为无法创建Visual C# 2015编译器。“Atlas2”已经是工作区的一部分。错误:由于无法创建Visual C# 2015编译器，因此无法打开项目'Atlas2‘。已添加具有相同密钥的项。有没有人能告

问为IIS配置ASP.NET应用程序后，加载该应用程序时出错
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