Thanks Chuck S for your reply but I think you got me wrong,
I've upgraded vbulletin to 3.6.3 not photopost.. An my gallery is empty now..
( actually 1 photo is left there.. )
Do I have to run any script from photopost to bring things back ?
upgrading your vbulletin forum would never delete your gallery thus is what I have posted above so if you would like support please post some links to your gallery so we can understand what your asking.