Isso acaba sendo um problema corrigido em KB4074880, " Conjunto de segurança e qualidade para o .NET Framework 4.6, 4.6.1, 4.6.2, 4.7 e 4.7.1 para Windows 7 SP1 e Server 2008 R2 SP1 ".
On January 18, 2018, update 4074880 was released to replace update 4055002 for .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, and 4.7.1 for Windows 7 SP1 and Windows Server 2008 R2 SP1. Update 4074880 no longer contains the issue that is described in the following Knowledge Base article:
4074906 - "TypeInitializationException" or "FileFormatException" error in WPF applications that request fallback fonts after you install the January 9, 2018, .NET Security and Quality Rollup (KB4055002)
Não há download para KB4074880; Eu o encontrei em Atualização do catálogo em KB4055532 .