I am using Notes 8.5.2 and I have found under shared action two design parent entries "Shared Actions", one with design version 8.5.2 and all the actions below, and one with version 6.5 without any actions.
I've deleted the 6.5 entry, and then it works.
Before it, I've got in Notes Client application in the info line the message "Note item not found" (in german: "Element des Dokuments nicht gefunden"),
in the browser application appeared a hard error interrupt with the message "HTTP Web Server: Lotus Notes Exception - Note item not found".
There is no need to delete all the shared actions and create them again!
Feedback response number WEBB8GYBXS created by c ifo on 05/18/2011