I just upgraded my VB from 3.0.13 to 3.5.4 . After the upgrade when I click on "Photos" on my VB board I see a blank page. I changed nothing in photopost.
You must be using Photopost 5.2x or above to be compatible with vbulletin 3.5x series. Therefore you need to upgrade to the latest Photopost which is 5.3