Rules stopped working

AndiRobinson Hello, are you using server-side or client-only rules? https://support.office.com/en-us/article/server-side-vs-client-only-rules-e1847992-8aa1-4158-8e24-ad043decf1eb If using the former you could create a new Outlook profile. It's not necessarily a "problem" receiving that prompt when you're using multiple rules while editing them, but you do mention that the rules don't apply any longer. As the problem suddenly appeared without interaction it's difficult to troubleshoot and perhaps your IT departments recommended solution is the way to go.

If your rules contains both options, the server-based rules are applied first followed by the client-only rules. Good to know.