Server crashing, seems to be from a plugin

When im restarting server i can play, all works fine, server is on Modded list in rust, and RCON works fine https://scr.hu/gVVd39p  (screenshot)
but after few minutes (3-5) i cant find my server, cant connect to server and RCON shows me https://scr.hu/ZBBzwmj (screenshot) and i cant do anything in RCON and cant connect again to server. I need to restart server again and again, and all the times after few minutes its repeat- works fine, 3-5 minutes later didnt work . Yesterday i didnt have this problems. It started ~3h ago. Looks like DDOS attack or something. 

I found reason of it- it was AdvertMessages plugin

here it is my all plugin list https://scr.hu/qNNkZGn (screenshot)

So can tell me why AdvertMessages crash my server? Maybe i have other plugin which connect to advertmessages and generate this bug?

Advert Messages is a pretty basic plugin, but if you suspect it has that issue, please use its support section and provide details with how you are reproducing the issue, any errors, etc.