We just installed the SharePoint 2019 - June 2026 update on our production environment and our flows are getting a “Fail on Start” error. If I create a new flow with sending an email, or updating a field, it works. But if I add a Switch, Run If, Set a Condition, the flow will not publish with an error “Failed to publish workflow: This feature has been temporarily disabled.”
The error in the logs is “Block the namespace: clr-namespace:System.CodeDom;Assembly=System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089, type: CodeBinaryOperatorExpression.Right “
I looked in the web.config and in the <System.Workflow.ComponentModel.WorkflowCompiler> <authorizedTypes> and the following exists:
<authorizedType Assembly="System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" NameSpace="System.CodeDom" TypeName="CodeBinaryOperatorExpression" Authorized="True" />
We apply the SharePoint update each month so it was working till last week. Is there any guidance on this, on how to resolve it.