(Solved) ERROR: .NET Framework Jan18 rollup known issue KB4074906

ISSUE SCOPE: A user running Windows 7.1 has reported an error that occurs on opening Castaway:

The invocation of the constructor on type 'Castaway.Gui.Components.Editors.FsRichTextBox' that matches the specified binding constraints threw an exception

EXPLANATION: This error is caused by a known issue that Microsoft has described in https://github.com/dotnet/announcements/issues/53

Essentially, there was a problem with the .NET Framework January 2018 Security and Quality Rollup (KB 4055002) released by Microsoft. This rollup was later fixed and re-released as KB 4074880.

SOLUTION: Microsoft sets out 3 options to fix this problem. They recommend using Option 1 first. If that does not succeed, they then recommend trying Options 2 and/or 3. The article provides more information, but in summary:

1. Run Fixit tool for KB4074906
   1. Download the tool from here: Microsoft Fixit tool 
      
      
2. Uninstall and re-install the January 2018 Monthly Rollup
   1. See the article for detailed instructions
      
      
3. Manually replace the GlobalUserInterface.CompositeFont
   1. Download the missing font file from: Microsoft font download
   2. Paste it to C:\Windows\Microsoft.NET\Framework\v4.0.30319\WPF\Fonts
   3. (NB you may need to login as administrator to do this)

If you encounter this error and cannot resolve it using any of these options, please contact our support team.