Crashing the server because a of a blaze

I was making a blaze farm, and when one or several blazes got stuck between a sticky piston and a solid block, the server crashed ("Disconnected from server" it says). After that I am unable to connect to the server for about 1-2 min. When I am able to log in, same thing happens. I can't perform any actions for the few seconds I am logged in. My friends who are not nearby my blaze farm, can play normally, but if I log in the whole server crashes. My friend tested to see if he got close to the farm it would crash, and it did.