System.Xml.XmlException: 给定编码中的字符无效。 第 1 行，位置 1。使用 Nuget 时

Question

For the last 24hrs Nuget seems to be throwing a weird error to me.

Everytime I try to install or uninstall a package.. it fails with the following error:

System.Xml.XmlException: Invalid character in the given encoding. Line 1, position 1.

The total stack is:

Attempting to gather dependencies information for package 'Microsoft.AspNet.WebApi.Client.5.2.3' with respect to project 'User Interface\SMRH.LPIC.Web', targeting '.NETFramework,Version=v4.5.1'
Attempting to resolve dependencies for package 'Microsoft.AspNet.WebApi.Client.5.2.3' with DependencyBehavior 'Lowest'
Resolving actions to install package 'Microsoft.AspNet.WebApi.Client.5.2.3'
Resolved actions to install package 'Microsoft.AspNet.WebApi.Client.5.2.3'
For adding package 'Microsoft.AspNet.WebApi.Client.5.2.3' to project 'SMRH.LPIC.Web' that targets 'net451'.
For adding package 'Microsoft.AspNet.WebApi.Client.5.2.3' to project    'SMRH.LPIC.Web' that targets 'net451'.
Package 'Microsoft.AspNet.WebApi.Client.5.2.3' already exists in folder   'F:\TFS\DevTeamCode\LPIC\SMRH.LPIC\packages'
Added reference 'System.Net.Http.Formatting' to project 'SMRH.LPIC.Web'.
Added package 'Microsoft.AspNet.WebApi.Client.5.2.3' to 'packages.config'
Successfully installed 'Microsoft.AspNet.WebApi.Client 5.2.3' to SMRH.LPIC.Web
Added file 'web.config'.
Install failed. Rolling back...
System.Xml.XmlException: Invalid character in the given encoding. Line 1, position 1.
at System.Xml.XmlTextReaderImpl.Throw(Exception e)
at System.Xml.XmlTextReaderImpl.Throw(String res, String arg)
at System.Xml.XmlTextReaderImpl.InvalidCharRecovery(Int32& bytesCount, Int32& charsCount)
at System.Xml.XmlTextReaderImpl.GetChars(Int32 maxCharsCount)
at System.Xml.XmlTextReaderImpl.ReadData()
at System.Xml.XmlTextReaderImpl.SwitchEncoding(Encoding newEncoding)
at System.Xml.XmlTextReaderImpl.SwitchEncodingToUTF8()
at System.Xml.XmlTextReaderImpl.ParseXmlDeclaration(Boolean isTextDecl)
at System.Xml.XmlTextReaderImpl.Read()
at System.Xml.Linq.XDocument.Load(XmlReader reader, LoadOptions options)
at NuGet.ProjectManagement.XmlUtility.LoadSafe(Stream input, LoadOptions options)
at NuGet.ProjectManagement.XmlUtility.GetDocument(String root, String path)
at NuGet.ProjectManagement.XmlUtility.GetOrCreateDocument(XName rootName, String root, String path, INuGetProjectContext nuGetProjectContext)
at NuGet.PackageManagement.VisualStudio.BindingRedirectManager.GetConfiguration()
at NuGet.PackageManagement.VisualStudio.BindingRedirectManager.AddBindingRedirects(IEnumerable`1 bindingRedirects)
at NuGet.PackageManagement.VisualStudio.RuntimeHelpers.<AddBindingRedirectsAsync>d__3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at NuGet.PackageManagement.VisualStudio.RuntimeHelpers.<AddBindingRedirectsAsync>d__2.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at NuGet.PackageManagement.VisualStudio.RuntimeHelpers.<AddBindingRedirectsAsync>d__2.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at NuGet.PackageManagement.VisualStudio.RuntimeHelpers.<AddBindingRedirectsAsync>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at NuGet.PackageManagement.VisualStudio.VSMSBuildNuGetProjectSystem.<<AddBindingRedirects>b__55_0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.VisualStudio.Threading.JoinableTask.CompleteOnCurrentThread()
at NuGet.PackageManagement.VisualStudio.VSMSBuildNuGetProjectSystem.AddBindingRedirects()
at NuGet.ProjectManagement.MSBuildNuGetProject.PostProcessAsync(INuGetProjectContext nuGetProjectContext, CancellationToken token)
at NuGet.PackageManagement.NuGetPackageManager.<ExecuteNuGetProjectActionsAsync>d__42.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at NuGet.PackageManagement.NuGetPackageManager.<ExecuteNuGetProjectActionsAsync>d__42.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at NuGet.PackageManagement.UI.UIActionEngine.<ExecuteActionsAsync>d__5.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at NuGet.PackageManagement.UI.UIActionEngine.<PerformActionAsync>d__3.MoveNext()
========== Finished ==========

It won't give me what file it is failing at. Deleting the packages folder and restoring it did not work either.

I have checked the web.config and it does not seem to have formatting issues.

Rebooted PC and VS but no luck.

Using Visual Studio 2015 Enterprise, with C# Environment.

Answer 1

I faced exactly the same issue. It was related to nuget cache. I cleared the cache and ran dotnet restore command again and it worked.

Command to clear cache: dotnet nuget locals all --clear

To restore nuget packages: dotnet restore --no-cache

Answer 2

Did you open and save the nuget config file in visual studio? I think the problem here is with the way Visual Studio encodes text files. I've fallen foul of it before. The solution is to open the file in a decent text editor like Notepad++ and change the encoding. The answer here should help Visual Studio inserts invalid characters in batch files .

The default location for NuGet's configuration file is %APPDATA%\\NuGet\\NuGet.Config (DOS) or $ENV:APPDATA\\NuGet\\NuGet.Config (PowerShell). APPDATA's value is OS, system drive, and current user dependent. For example: D:\\Users\\username\\AppData\\Roaming\\NuGet\\NuGet.config.

Taken from https://docs.nuget.org/consume/nuget-config-file

Answer 3

I found this to be an encoding problem. If you open the file in visual studio code you will see that the encoding might be UTF-8 with BOM (it should appear on the bottom left corner). Some parsers have difficulty reading the BOM when interpreting files.

Try saving the file just as UTF-8 Encoding (in vs code this can be done by clicking on the encoding and selecting the option save as).

Hope this helps.

Answer 4

I kept getting this error using VS2019 and I was uninstalling and reinstalling NuGets clearing the cache as a workaround as mentioned in the other answer.

What actually worked for me was doing a Visual Studio repair .

After I've done the repair I faced a few more errors regarding Unable to find project information for... but that got cleared by running dotnet nuget locals all --clear command. Now it works like a charm!