Last time I got the way to know how many users liked a photo with this way:
https://graph.facebook.com/161820597180936/likes?limit=1000
But I don’t know why it doesn’t work anymore. Now it only returns 3 or 4 facebook users in the case they work very well before. It happened 2 days ago, so I guess facebook changed something in it’s API. Any suggestions on how to solve this problem?
This is a bug in the Graph API, and should eventually be fixed by Facebook.
Facebook has pledged to provide 90 day notifications before making breaking changes to the API, so it is important to file bugs even if you assume that a change was intentional but there was no prior notification.