POSSIBLE CAUSES OF SERVER NOT STARTING:
Here are a few causes of why your server may not start:
1. You have no more disk space. This will show in console as “Out of Space”
2. You have chunk corruption in your world(s)
3. There is a plugin error
DIFFERENT LAGS AND POSSIBLE CAUSES:
1. Delays in typing, block breaking, damage or movement:
a. This type usually is due to: client’s own internet, issues with plugins or your world, and very rarely, network lag on the host’s side. A good plugin to have is called LagMeter. In game type the /lag command if you start feeling lag. If the TPS is near 20, then the issue is not related to the network.
2. Barely can look around – this is on the client side and is a framerate.
b. This is usually due to chunk generation. Too much TNT can cause this. Sometimes, also outdated plugins can be the cause.