Well playing on this server I found out that its on peaceful, abd with this I can not get the credits to advance forward in my efforts. So I would like to see this change in some time forward and maybe even make the server change by adding more things to do later.

The server is only on peaceful until a bug is fixed. 

All mobs drop credits, not only aggressive mobs

peaceful isn't what's stopping you from getting credits but your negligence to look for other mobs

although some items can't be obtained in peaceful, we need to put the server on peaceful until we find a solution to this bug as stated above 

stop complaining all your doing is making things worse

EDIT: Wrong thread, sorry.