Today Widget on OS X not working

Question

I can't seem to get my Today widget (or any extension for that matter) running in the Widget Simulator. The simulator launches and says "Couldn't Open Widget" along with

Failed to find Widget /Users/SomeUser/Library/Developer/Xcode/DerivedData/Build/Products/Debug/MyApp.app/Contents/PlugIns/MyApp.appex

I looked in Console app and I see this as well:

pkd[299]: ignoring mis-configured plug-in at /Users/SomeUser/Library/Developer/Xcode/DerivedData/Build/Products/Debug/MyApp.app/Contents/PlugIns/MyApp.appex: plug-ins must be sandboxed

But it is sandboxed in xcode! It's codesigned, sandboxed and the lot. Even if I try and deploy it on a new machine (registered as a developer machine with my developer provisioning profile), the widgets don't even show up in System Preferences.

Any idea what I need to do?

Answer 1

Okay finally found the problem. I was codesigning my app by hand (which had never been a problem before) since I had an intricate set of frameworks the app relied upon, and needed to hand copy them using a Copy / Runscript post-build script. Any way, it seems starting Xcode 7 at least, this no longer works as expected. The app works and codesign says the app has been signed correctly, but clearly something is happening behind the scenes that's breaking the codesignature. I ended up removing all my manual codesigning stuff and simply using Xcode's 'Copy Framework' post build step and checked 'Sign on Copy'. It's now finally working as expected.