In a previous blog post I talked about how to use SignalR with your DotNetNuke modules, well, if you are using DNN 7.1 and the "Advanced" URLFormat option (upgrades won't use this by default, new installs will) then the SignalR/Hubs route will no longer work, DNN will return a 404 for that path.

What you need to do is "override" the URL settings in DNN. In the DNN Platform, you have to do this manually, via the database, I believe the EVOQ ($paid$) versions have a UI for this, but for those of us who focus specifically on the open source platform, you need to make manually update database entries to customize the URL handling in 7.1+.