Facebook campaign image preview not loading

[大田]

Hello,

I have recently set up the facebook app in order to manage avertisement campaigns, but the ad preview doesn't want to load (see picture). Or rather it seems to be loading but then stays blank. I have tried with Firefox and Google Chrome, same issue. I have checked the catalogue and the items have been reviewed and accepted for advertising (although not for sales, if that matters).

Anyone got an idea ?

Thank you.