Please read this page before using the SnowManager in the plugin
The SnowManager place and remove blocks in your world, so you should make a backup before.
It can cause serious lag on the client because of sending update about blocks very fast
The solutions are :
- decrease the Speed of the SnowPlace and SnowRemove in the configs (nice values are 0.1 - 2)
- Reduce the distance-view in the server.properties
In fact The Snow is put on the rain time and is removed during the sun time
You can set the speed to 0 to don't active it