If Tinder is telling you it cannot find any pictures, and you've gone through the obvious things such as increasing your range or moving your pictures to a different Facebook album, then your problem may have been caused by a major upgrade Tinder underwent in June 2014.
1. Reset the authorization process via your Facebook app, via 'privacy shortcuts,' and selecting 'remove Tinder.' Once you've re-added Tinder, the upgrade will kick in and you should be back to normal.
2. On your iPhone, ensure 'background app refresh' is selected. If you had not selected this previously, you would not have been able to use Tinder after the upgrade.
Tinder have been working on these issues and newcomers to Tinder should not have any difficulties.