How to make my server private? And why does my server go on hibernating mode?

[Mesti]

How do I make my server private? People in my server made all the villagers in a village in my server disappear and dug straight down in a villager's house. I tried making my server not visible and I put /whitelist on in my server panel but every time my server goes to hibernating mode after I do something to it.

(please don't say I'm stupid)

Edited January 28, 2021 by Mesti

[SkripterMan]

5 hours ago, Mesti said:

How do I make my server private? People in my server made all the villagers in a village in my server disappear and dug straight down in a villager's house. I tried making my server not visible and I put /whitelist on in my server panel but every time my server goes to hibernating mode after I do something to it.

(please don't say I'm stupid)

What plugins do you have on your server? Also, could you send your server logs?