some short questions: Is it possible to create in an Firefox-AddOn an network protocol? Like player:// that triggers the network protocol popup and where the user self must choose an application or is this only possible with an entry in the operating system settings?
So tabs.update() functioned again in the newest update and the answer for my questions is:
Only an network protocol scheme to special html-page is possible with registerProtocols or manifest.
Only os-specified settings accept firefox as an out-of-firefox enviroment link and a os-special open as popup.