SharePoint 2010 Workflow conditions not working upon Publish

Question

I have some existing workflows that all of a sudden stopped working - around September 12, 2018. I tried many things: I looked at logs, .NET updates, cache issues, etc. and I can't get to the source of this issue. I went into the workflows and noticed that the conditions are the ones giving me an error when I try to publish, which is a big deal because my workflows depend on those conditions - IF conditions mostly.

Some of the errors I get say this below:

• FIRST WORKFLOW:

(-1, -1) Type System.CodeDom.CodeBinaryOperatorExpression is not marked as authorized in the application configuration file.)

(0, 0) Activity 'ID179' validation failed: Property "Condition" has invalid value. Condition expression is invalid. The condition expression can not be null.)

(0, 0) Activity 'ID5' validation failed: Property "Condition" has invalid value. Condition expression is invalid. The condition expression can not be null.)

---

• SECOND WORKFLOW:

(-1, -1) Type System.CodeDom.CodeBinaryOperatorExpression is not marked as authorized in the application configuration file.)

(0, 0) Activity 'ID7' validation failed: Property "Condition" has invalid value. Condition expression is invalid. The condition expression can not be null.)

(0, 0) Activity 'ID12' validation failed: Property "Condition" has invalid value. Condition expression is invalid. The condition expression can not be null.)

Do any of you know what is causing this? The workflows were working perfectly fine before.

Any help will be appreciated. Thanks!

Answer 1

There has been an issue where a .Net patch causes workflows to fail.

https://blogs.msdn.microsoft.com/rodneyviana/2018/09/13/after-installing-net-security-patches-to-address-cve-2018-8421-sharepoint-workflows-stop-working/

And here is the KB article. https://support.microsoft.com/en-nz/help/4465015/sharepoint-workflows-stop-after-cve-2018-8421-security-update