SharePoint2010 Workflow Error

Question

We just started getting the following errors when trying to run simple "out of the box" workflows. The workflow history shows an Event Type of “Workflow Cancelled” and the description is “Workflow My Test Approval Workflow was canceled by System Account.”

ULS logs show the following error:

RunWorkflow: Microsoft.SharePoint.SPException: at Microsoft.SharePoint.Workflow.SPNoCodeXomlCompiler.LoadXomlAssembly(SPWorkflowAssociation association, SPWeb web) at Microsoft.SharePoint.Workflow.SPWinOeHostServices.LoadDeclarativeAssembly(SPWorkflowAssociation association, Boolean fallback) at Microsoft.SharePoint.Workflow.SPWinOeHostServices.CreateInstance(SPWorkflow workflow) at Microsoft.SharePoint.Workflow.SPWinOeEngine.RunWorkflow(SPWorkflowHostService host, SPWorkflow workflow, Collection 1 events, TimeSpan timeOut) at Microsoft.SharePoint.Workflow.SPWorkflowManager.RunWorkflowElev(SPWorkflow workflow, Collection 1 events, SPWorkflowRunOptionsInternal runOptions)`

Answer 1

For others that are experiencing this issue. Here is the article that had the fix for this. This is a known issue with the September 2018 .NET patch updates. This causes SharePoint out of the box Workflows to stop working. https://blogs.msdn.microsoft.com/rodneyviana/2018/09/13/after-installing-net-security-patches-to-address-cve-2018-8421-sharepoint-workflows-stop-working/