Exception ticking world & server tick loop

[MinervaMinecraft]

Started playing the updated Ferret Business modpack again recently, love that it's still around. Unfortunately it recently started crashing on me and the game became unplayable.

It crashed when I entered the nether thorugh the same portal which I used a few times before. The nether it was crowded with mobs when I teleported to it so I figured it might be too heavy on my machine in terms of FPS. So I reduced all the video settings to a minimum, but that didn't work. Also updated Java, checked if I had the correct version of (Curse)Forge (running it on version 10.13.4.1614 which I believe is the correct one), and added the BetterFPS mod for 1.7.10 (I know its not in the modpack but I had good results with it when I used to run a server and it doesnt look like its adding any harm). Also turned off snooper settings, allocated extra memory in CurseForge for Minecraft and finally deleted the content of the DIM-1 folder. That last one at least managed to get me into the (reset) nether but when I tried to go back to the overworld it still crashed. The game also still keeps regulary crashing IN the nether when I try to get back in. I am playing a fresh game, not an updated old game, so its not likely that is has to do with old questing settings.

I get 2 different types of error. Mostly Exception ticking world - java.util.ConcurrentModificationException

but also sometimes Exception in server tick loop - java.lang.ArrayIndexOutOfBoundsException: -1 which seems to point at MF reloaded and thermalDynamics. I do not use these mods in the nether but obvisously I do in the overworld, which I have no way of accessing atm. I am worried that simply deleting these mods would corrupt my game, and if not its really no fun playing the modpack without them so I hope that there's an alternative (also not convinced that this would solve the issue given my description above). I also do not really have a reason to think these mods are causing any issues, apart from a MF chunkloader machine in the overworld (that did not cause issues before, but perhaps by TPing to the nether I unloaded the chunk it was on and that caused this..? Pure guesswork though).

I am running out of options here and had tons of fun playing so any help would be greatly appreciated!

[CaiganMythFang]

Greetings!

Glancing through the logs and poking at some githubs while I have the time, this might be an odd issue that might be tough to track down the root cause....but some things to try.

If you are using the MF chunkloader, you may try swapping to the FTB Utilities chunkloading instead, since it works a little nicer with the forge chunkloading system in 1.7 (from my memory at least?). In your inventory, click the Map icon to the left of the portrait, claim a chunk with left click, then hold CTRL when left clicking a claimed chunk to Chunkload that chunk.

I would give that a shot, and turn off (probably outright break and pick up) the MF chunkloading machine and see if that stops the crashes..

[MinervaMinecraft]

Thanks for the reply! I would have disabled the MF chunkloader if I could enter my overworld. Unfortunately I haven't been able to as it keeps crashing. Any suggestions as to how I could approach that alternatively?

[CaiganMythFang]

There's a few options you have:

1) Try changing the Forge chunkloading configs. This is the easiest but also one that may not work because not all mods tied into forges chunkloading in earlier versions (I don't remember of MFR did.)

In the config folder, open forgeChunkLoading.cfg and change the following (I'll put the defaults here so you can change them back afterewards :

I:maximumTicketCount=0 (Default : 200)

# Are mod overrides enabled?
    B:enabled=false (Default : true)

2) Try disabling Thermal Dynamics and associated mods just long enough to get into the overworld to turn off the chunkloader. You'll script errors, and ANY items you have from those mods and any ores or placed blocks in the world will be deleted, however. Since you said you don't use these mods right now, you wouldn't have to replace any machines or constructions with them, but you would lose ores.

This also doesn't guarantee the crash won't happen, as it could be these are just the first mods that the crash 'points' to.

3) Try disabling MFR. It would stop the chunkloader, but also have the same issue of deleting all items and blocks in the world.

4) Use MCEdit to edit the world, find the chunkloader, and delete it specifically. This is definitely the much more complex option if you've never used MCEdit. I give this one as the last option as I've done this a few times and I'd prefer option 1 or 2 first.