Not all bricks loading but it shows all bricks loaded out of all

[Robo Dude]

Me and my friend have been working on a huge town we finished most of it today. but i was there the whole time so it couldnt got ripped apart. then when he loads it later its missing like all the bricks just the plates and baseplates. but all same add ons enabled none missing.anyhelp?

[Ad Bot]

[K3k0m@n]

me and my friend made a zombie map and we loaded it on my other friend's server and half of it was gone.
and the host did have the bricks, so i went into singleplayer and loaded it and it was all there.