Physical system will not work in some world

[Ovear]

i am using cauldorn and Multiverse to create new custom world.(with minecraft 1.7.10)
In the new world created by myself, the Physical system won't work, but the other systems works.
In the nether and the default world, all of the system works. There are not any error print on server's console

[Ovear]

em...it will be normal after some hours..and if i restart server..it will still not working.