Assuming the “Invalid OAuth 2.0 Access Token” bug is fixed (at least for many of the possible cases) and it is not that “hot” now, then I think the new “Hottest Bug” will be
“Sorry, something went wrong. We’re working on getting this fixed as soon as we can.”
According to what have been reported, this problem happens in the process of registering an Facebook application in the Facebook’s Developer Home. And having this error message displayed simply means that you cannot register the Facebook application successfully.
At this moment, what I can tell is that this is not a”hard problem”. Some people reported that by retrying, retrying …… and retying (i.e. it is not simply retrying the process once or twice, but many, many times), they can still have their application registered.
Also, when this problem happens, it does not mean all the users will encounter this. At least I have an experience that when one of my clients reported that they cannot register the app, I can still register the application. FYI, at that time, I was asking him to register the app online via Skye, he did it, got the error and told me immediately, so the delay is pretty short.
In fact, up to now, I have not experienced this error… and I hope this won’t happen to me!