title: Errors using GAC_MSIL assemblies on VSTS
body: <p>I have an ASP web form Project stored in VSTS, and I am trying to build it. Suddenly I got this error in the build section:</p>
  
  <pre><code>2017-04-18T22:01:20.3859517Z Build FAILED.
  2017-04-18T22:01:20.3859517Z 
  2017-04-18T22:01:20.3869498Z "d:\a\1\s\WebTimeSheet.sln" (default target) (1) -&gt;
  2017-04-18T22:01:20.3869498Z "d:\a\1\s\WebTimeSheet\WebTimeSheet.csproj" (default target) (2) -&gt;
  2017-04-18T22:01:20.3869498Z (ResolveComReferences target) -&gt; 
  2017-04-18T22:01:20.3869498Z   C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.Common.CurrentVersion.targets(2399,5): warning MSB3284: Cannot get the file path for type library "2df8d04c-5bfa-101b-bde5-00aa0044de52" version 2.5. Library not registered. (Exception from HRESULT: 0x8002801D (TYPE_E_LIBNOTREGISTERED)) [d:\a\1\s\WebTimeSheet\WebTimeSheet.csproj]
  2017-04-18T22:01:20.3869498Z   C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.Common.CurrentVersion.targets(2399,5): warning MSB3284: Cannot get the file path for type library "00020813-0000-0000-c000-000000000046" version 1.7. Library not registered. (Exception from HRESULT: 0x8002801D (TYPE_E_LIBNOTREGISTERED)) [d:\a\1\s\WebTimeSheet\WebTimeSheet.csproj]
  2017-04-18T22:01:20.3869498Z   C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.Common.CurrentVersion.targets(2399,5): warning MSB3284: Cannot get the file path for type library "00020905-0000-0000-c000-000000000046" version 8.5. Library not registered. (Exception from HRESULT: 0x8002801D (TYPE_E_LIBNOTREGISTERED)) [d:\a\1\s\WebTimeSheet\WebTimeSheet.csproj]
  2017-04-18T22:01:20.3869498Z   C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.Common.CurrentVersion.targets(2399,5): warning MSB3284: Cannot get the file path for type library "0002e157-0000-0000-c000-000000000046" version 5.3. Library not registered. (Exception from HRESULT: 0x8002801D (TYPE_E_LIBNOTREGISTERED)) [d:\a\1\s\WebTimeSheet\WebTimeSheet.csproj]
  2017-04-18T22:01:20.4149496Z 
  2017-04-18T22:01:20.4149496Z 
  2017-04-18T22:01:20.4149496Z "d:\a\1\s\WebTimeSheet.sln" (default target) (1) -&gt;
  2017-04-18T22:01:20.4149496Z "d:\a\1\s\WebTimeSheet\WebTimeSheet.csproj"     (default target) (2) -&gt;
  2017-04-18T22:01:20.4149496Z (CoreCompile target) -&gt; 
  2017-04-18T22:01:20.4149496Z   Helpers\ExcelDataBuilder.cs(6,17): error CS0234: The type or namespace name 'Office' does not exist in the namespace 'Microsoft' (are you missing an assembly reference?) [d:\a\1\s\WebTimeSheet\WebTimeSheet.csproj]
  2017-04-18T22:01:20.4149496Z   Helpers\WordInvoiceBuilder.cs(5,17): error CS0234: The type or namespace name 'Office' does not exist in the namespace 'Microsoft' (are you missing an assembly reference?) [d:\a\1\s\WebTimeSheet\WebTimeSheet.csproj]
  2017-04-18T22:01:20.4149496Z   Helpers\ExcelDataBuilder.cs(127,104): error CS0246: The type or namespace name 'Worksheet' could not be found (are you missing a using directive or an assembly reference?) [d:\a\1\s\WebTimeSheet\WebTimeSheet.csproj]
  2017-04-18T22:01:20.4149496Z   Helpers\ExcelDataBuilder.cs(166,80): error CS0246: The type or namespace name 'Worksheet' could not be found (are you missing a using directive or an assembly reference?) [d:\a\1\s\WebTimeSheet\WebTimeSheet.csproj]
  2017-04-18T22:01:20.4149496Z   Helpers\ExcelDataBuilder.cs(18,17): error CS0246: The type or namespace name 'Application' could not be found (are you missing a using directive or an assembly reference?) [d:\a\1\s\WebTimeSheet\WebTimeSheet.csproj]
  2017-04-18T22:01:20.4149496Z   Helpers\WordInvoiceBuilder.cs(172,143): error CS0246: The type or namespace name 'Document' could not be found (are you missing a using directive or an assembly reference?) [d:\a\1\s\WebTimeSheet\WebTimeSheet.csproj]
  2017-04-18T22:01:20.4149496Z   Helpers\WordInvoiceBuilder.cs(19,17): error CS0246: The type or namespace name 'Application' could not be found (are you missing a using directive or an assembly reference?) [d:\a\1\s\WebTimeSheet\WebTimeSheet.csproj]
  2017-04-18T22:01:20.4149496Z 
  2017-04-18T22:01:20.4149496Z     4 Warning(s)
  2017-04-18T22:01:20.4149496Z     7 Error(s)
  </code></pre>
  
  <p>I am using Hosted Queue to build the project. I have tried to get a local copy of the asemblies, include them into the project (/bin) and upload them, but it does not work. ¿How Can I include them into the build so I can avoid this error?</p>
  
  <p>If I build the project in my local using Visual Studio Community 2015, works fine (the aseemblies are already included in references).</p>
  
  <p>I have no private agents (just using Hosted). My build configuration was default build. Everythign else by defaul. NuGet restore, .sln root path, default visual studio build and no test assemblies.</p>
  
  <p>Sorry if I forgot something else.</p>
  
  <p>Many thanks,</p>