1.6.1 Mob Spawning Issue

So when I first start my server and I go to spawn say a horse or something like that then in about a minute or so I try to spawn a mob again and it won't spawn anything which is weird I have even tried logging out and logging back in but nothing seems to work except restarting my server. How can I fix this issue?

 

Can you reproduce without plugins? Can you provide your full server.log in a pastebin please?

 

I have not tried that and there is no error in the server.log. Mobs still spawn automatically I just can't manuallyspawn a mob.

 

Please pastebin your full server.log

 

I can spawn mobs by command but not with spawn eggs.

Edit:I think it would be fixed if essentials was updated to 1.6.1

 

essentials cannot block spawn eggs only, so no.
also there is a dev version for 1.6.1

 

I think I have the latest one but i'll check.

Edit: Yeah I have the latest dev build.