I'm a codeveloper on a website which has a Facebook like button, and for this an App ID has been created at some point in the past and added to the meta headers.
The problem is we are not sure who created that App ID in the past, so that we can change the app's settings etc. A solution would simply be to make a new app for the site, but I'm curious if that's really necessary? I found an old Stack Overflow question on the topic, however those solutions no longer seem to be working, and AFAICS we only use the App ID of the site at the moment, not any secret key or access token. (That is we don't know what those are, if they have been created.)