I am playing the Big Dig mod pack using the Technic Platform. Up until about a day ago, my world was pretty normal – creepers, slimes, etc. However, now it seems that I don't have any hostile mobs spawning.
I think it might have to do with when I fell through the bottom of the world after going too deep into multiple Dimensional Doors…when I came out, I was 20+ kilometers from home in the middle of the ocean, where I found a huge dungeon full of spawners. I raided the dungeon for awhile and then spent a long time trekking back to my base.
Are there any "quick fixes" I should try to see if I can get mobs to start spawning again? Could it be the "Mob Extinction" issue? What should I do?
EDITED TO ADD: I think I have at least a partial confirmation that the issue has to do with spawn limits, etc. I traveled to the Nether last night for some Nether stuff, and there were Ghasts a-plenty, along with Zombie Pigmen and Blazes. Also, monster spawners still work in the Overworld – it just seems that there's no random spawns.
Best Answer
This was related to the Dimensional Doors mod, and it is now resolved with newer versions (I am running 1.3.2 with my install of Big Dig and it is all fine, and mobs are back).
Reference can be found here.