title: how to resolve "error MSB3188: Assembly ... must be strong signed in order to be marked as a prerequisite."
body: <p>I've seen several questions on this board which are similar, but I think several problems can cause this message, and my particular problem may not have been among them, and certainly my solution appears much simpler and more effective than any of the others.</p>
  
  <p>I have a project which was using packages.config.</p>
  
  <p>I used the Visual Studio UI to migrate by projects references from package.config to PackageReference (<a href="https://devblogs.microsoft.com/nuget/migrate-packages-config-to-package-reference/" rel="nofollow noreferrer">https://devblogs.microsoft.com/nuget/migrate-packages-config-to-package-reference/</a>). I did this because it allows building with msbuild /t:restore mysln.sln - which doesn't work with packages.config.</p>
  
  <p>I think this GENERALLY works (I tried 5 or 6 times on other projects). But on one project when I rebuilt, I got the error message:</p>
  
  <pre><code>c:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Microsoft\VisualStudio\v16.0\OfficeTools\Microsoft.VisualStudio.Tools.Office.targets(236,9): error MSB3188: Assembly 'C:\Users\lew
  is\.nuget\packages\mousekeyhook\5.6.0\lib\net40\Gma.System.MouseKeyHook.dll' must be strong signed in order to be marked as a prerequisite.
  </code></pre>