Minecraft Server error: Can't keep up! Is the server overloaded? Running 2047ms or 40 ticks behind?

Ch
- in Plugins
2

"Can't keep up! Is the server overloaded? Running 2047ms or 40 ticks behind"

I gave my friend a Minecraft server and he said that the server is down smeared and this error is in the console (there are no plugins on the server and only 3 players and he has 1gb ram). How can I fix this?

St

The server is too slow.

de

Maybe book more RAM, otherwise maybe the world has "a way", because usually only helps to create a backup or completely new.