Hello,
we implemented an async block controller in our project, using the approach described here http://world.episerver.com/forum/developer-forum/Developer-to-developer/Thread-Container/2015/9/async-actionresult/ . We had Epi server version 8.xxx. However, after upgrading to 9.12 this stopped working. We stargted getting errors like:
HttpServerUtility.Execute blocked while waiting for an asynchronous operation to complete.
It is interesting that async actually works, when inheriting form BlockController. Action results can be async, but they need to be different from Index(). If you have async Index() and inherit from AsyncBlockController, we get the error.
Additionally, in MVC there is a restriction that child actions cannot be asynchronius. Is it possible Epi server to have changed something in the rendering in the newer version?