I'm curious if anyone has had the issue described here: https://blogs.msdn.microsoft.com/dotnet/2018/09/11/net-framework-september-2018-security-and-quality-rollup/
After any of the September 2018 .NET Framework security updates to resolve CVE-2018-8421 (.NET Framework Remote Code Execution Vulnerability) are applied, SharePoint out-of-the-box workflows stop working.
The November CU lists that it resolves this issue, but when I applied the update I was still unable to use an out of the box 2010 workflow. I can see in central admin that the update has been installed successfully.
Here's the article for resolving the issue: https://support.microsoft.com/en-us/help/4465015/sharepoint-workflows-stop-after-cve-2018-8421-security-update
The solution is to explicitly add the necessary types to all web applications' web.config files.
I checked the web.config file and the additional settings outlined in the article were not present. I'm wondering if I still need to make these changes to the web.config file.