Due to recent bindings changes (https://github.com/xamarin/xamarin-macios/commit/6c3fee4ddfa202fb50e0af216102a69b80477c65) the Broadcast UI template is broken.
"ExtensionContext.CompleteRequest" needs "NSDictionary<NSString, INSCoding>" instead of "NSDictionary<NSString, NSCoding>".
Fixed in md-addins:master (d47ff24ca3fd500018bc6fc9b60769e4b5024d3c) and cycle8 PR (https://github.com/xamarin/md-addins/pull/1218).
I have checked this issue and observed that this issue has been fixed as shown in the screencast : http://www.screencast.com/t/cFovGGgJDMs
Hence closing this issue by marking it as Verified.
Addition in comment 2 : Using Master build of XamarinStudio-220.127.116.114_f6483f8a1c6d0790f2d8033a7e4d55e09b57a8bd
I have checked this issue with latest build of C8SR0 and observed that the fix for this issue has been merged in C8SR0 XamarinStudio-18.104.22.168 d8b32f2e91a12d368b5653aa035cde654d38bd53
Screencast : http://www.screencast.com/t/qDoCnGxP8804