I recently updated from spigot 1.8 to 1.8.7 due to a sign crash hitting my server.

This did fix the sign crash from the hacked client, but I am now seeing no mobs spawning. This is quite an issue for me as my server is a survival server, and there is no fun in a survival server without monsters. I have tried using previous builds, and the most recent up to date build of spigot. But still nothing works. I do not think there is an issue with my plugins either, as I have not added any new plugins since the time it used to spawn monsters.

The only thing I have changed that has caused this, was the Spigot version.

Other people have had this same problem too at: https://www.spigotmc.org/threads/1-8-7-and-mob-spawn-rates.71234/

I can give a full plugin list if that is necessary. But I do not think that is the problem.