I was just done with work, and thought to play a game of Destiny, when much to my dismay, I encountered the subject-line error. The exact sequence of events was thus:
Turn on Console.
Highlight "Destiny" in my Home screen.
Wait 15-20s at the Destiny full-screen Splash Screen.
Get error "Sorry, we were not able to start your game or app. Please try again. If you see this message again, please restart your console. (0x87de0003)".
I restarted my console. I followed the procedures described here:
Neither of which resolved the issue. I attempted an uninstall and then a reinstall, but the install will only reach 1% before failing out with the same error.