that photopost link tells me it does exist cause ya have a trailing )
but anyway I would suggest you turn on php errors or check error logs on server for something that might assist. There has to be something that changed when you upgraded cause a normal upgrade would not break the gallery.
Check your config-int.php file and turn off the vb3 options and turn them to off and see if page loads.
Did you change table prefix or anything on vb
upgrade there would have to be something that is different