lsquo;Softie Rodney Viana has posted details and a workaround for the &System.CodeDom.CodeBinaryOperatorExpression is not marked as authorized& bug.
Apparently, installing last Tuesday KB 4457916 Security Only updates for .Net Framework 3.5, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, and 4.7.2 for Windows 8.1 and Server 2012 R2 causes a hard stop with any SharePoint Workflows.
(Workflows are set up by an admin to handle the flow of documents through a series of steps.)