I just created a new MonoGame project in Xamarin and it doesn't work

Hello,

I tried to create a new solution and just after that run the project, but it does throw an error to me as soon as I try to compile it. The error says

Error: /Users/Martin/Projects/textXNA3/textXNA3/textXNA3.csproj: Input string was not in a correct format. (textXNA3)

I have no idea why. My csproj (not touched) looks like this. What’s the matter?

<?xml version="1.0" encoding="utf-8"?>
<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <Import Project="$(MSBuildExtensionsPath)\MonoGame\v3.0\MonoGame.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\MonoGame\v3.0\MonoGame.Common.props')" />
  <PropertyGroup>
    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
    <Platform Condition=" '$(Platform)' == '' ">x86</Platform>
    <ProjectGuid>{5C447E41-B379-41BA-B71B-5BD56CA39438}</ProjectGuid>
    <ProjectTypeGuids>{A3F8F2AB-B479-4A4A-A458-A89E7DC349F1};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
    <OutputType>Exe</OutputType>
    <RootNamespace>textXNA3</RootNamespace>
    <AssemblyName>textXNA3</AssemblyName>
    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
    <MonoMacResourcePrefix>Resources</MonoMacResourcePrefix>
    <MonoGamePlatform>DesktopGL</MonoGamePlatform>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|x86' ">
    <DebugSymbols>true</DebugSymbols>
    <DebugType>full</DebugType>
    <Optimize>false</Optimize>
    <OutputPath>bin\Debug</OutputPath>
    <DefineConstants>DEBUG;</DefineConstants>
    <ErrorReport>prompt</ErrorReport>
    <WarningLevel>4</WarningLevel>
    <EnableCodeSigning>false</EnableCodeSigning>
    <CodeSigningKey>Mac Developer</CodeSigningKey>
    <CreatePackage>false</CreatePackage>
    <EnablePackageSigning>false</EnablePackageSigning>
    <IncludeMonoRuntime>false</IncludeMonoRuntime>
    <UseSGen>true</UseSGen>
    <UseRefCounting>true</UseRefCounting>
    <PlatformTarget>x86</PlatformTarget>
    <IntermediateOutputPath>obj\x86\Debug</IntermediateOutputPath>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|x86' ">
    <DebugType>pdbonly</DebugType>
    <Optimize>true</Optimize>
    <OutputPath>bin\Release</OutputPath>
    <ErrorReport>prompt</ErrorReport>
    <WarningLevel>4</WarningLevel>
    <EnableCodeSigning>false</EnableCodeSigning>
    <CreatePackage>true</CreatePackage>
    <EnablePackageSigning>false</EnablePackageSigning>
    <IncludeMonoRuntime>true</IncludeMonoRuntime>
    <UseSGen>true</UseSGen>
    <UseRefCounting>true</UseRefCounting>
    <LinkMode>SdkOnly</LinkMode>
    <PlatformTarget>x86</PlatformTarget>
    <IntermediateOutputPath>obj\x86\Release</IntermediateOutputPath>
  </PropertyGroup>
  <ItemGroup>
    <Reference Include="System" />
    <Reference Include="System.Xml" />
    <Reference Include="System.Core" />
    <Reference Include="System.Xml.Linq" />
    <Reference Include="System.Drawing" />
    <Reference Include="Xamarin.Mac" />
    <Reference Include="MonoGame.Framework">
      <HintPath>..\packages\MonoGame.Framework.DesktopGL.3.6.0.1625\lib\net40\MonoGame.Framework.dll</HintPath>
      <Private>False</Private>
    </Reference>
  </ItemGroup>
  <ItemGroup>
    <Compile Include="Game1.cs" />
    <Compile Include="Main.cs" />
    <Compile Include="Properties\AssemblyInfo.cs" />
  </ItemGroup>
  <ItemGroup>
    <None Include="Info.plist" />
    <None Include="packages.config" />
  </ItemGroup>
  <ItemGroup>
    <EmbeddedResource Include="Icon.ico" />
  </ItemGroup>
  <ItemGroup>
    <MonoGameContentReference Include="Content\Content.mgcb" />
  </ItemGroup>
  <ItemGroup>
    <Content Include="MonoGame.Framework.dll.config">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </Content>
  </ItemGroup>
  <ItemGroup>
    <NativeReference Include="libopenal.1.dylib">
      <Kind>Static</Kind>
    </NativeReference>
    <NativeReference Include="libSDL2-2.0.0.dylib">
      <Kind>Static</Kind>
    </NativeReference>
  </ItemGroup>
  <Import Project="$(MSBuildExtensionsPath)\Xamarin\Mac\Xamarin.Mac.CSharp.targets" />
  <Import Project="$(MSBuildExtensionsPath)\MonoGame\v3.0\MonoGame.Content.Builder.targets" />
</Project>