http://www.minecraftforum.net/forums/mapping-and-modding/minecraft-mods/1288431-just-another-spawner-jas-v0-14?comment=2108

Having gazillions of config files, I'm pretty sure I dun goof'd somewhere, because I'm getting crashes with my config files, but none with regenerated ones.

Is there an easy way to check for syntax mistakes?

Edit: Crashreport http://hastebin.com/irinodubol.1c

http://www.minecraftforum.net/forums/mapping-and-modding/minecraft-mods/1288431-just-another-spawner-jas-v0-14?comment=2117

Coming back to this, I had a notion. Could it be that ConcurrentModificationException occur more often with so called Chunkloaders active? Like the Worldanchor or Chickenbones Chunkthingy?

I'm asking because I've got 2 anchors set up at 2 different bases, each about 2000 blocks apart. The anchor supposedly keeps a 9x9x9 area always loaded. Seeing how you explained what ConcurrentModificationException is, I don't think it's so far out to assume chunk loaders could be an or the issue.

Now, I like to go out and explore, like way, way, way, way out of my way 10+k blocks away from the anchored chunks. Might this be what causes these crashes?

Occurs while entitytracker is iterating over the entitestrackers w/ entities to update them.
i.e.

    public void updateTrackedEntities() {
        ArrayList arraylist = new ArrayList();
        Iterator iterator = this.trackedEntities.iterator();

        while (iterator.hasNext()) {
            EntityTrackerEntry entitytrackerentry = (EntityTrackerEntry) iterator.next();
            entitytrackerentry.sendLocationToAllClients(this.theWorld.playerEntities);

            if ((entitytrackerentry.playerEntitiesUpdated) && (entitytrackerentry.myEntity instanceof EntityPlayerMP)) {
                arraylist.add((EntityPlayerMP) entitytrackerentry.myEntity);
            }
        }

        for (int i = 0; i < arraylist.size(); ++i) {
            EntityPlayerMP entityplayermp = (EntityPlayerMP) arraylist.get(i);
            Iterator iterator1 = this.trackedEntities.iterator();

            while (iterator1.hasNext()) {
                EntityTrackerEntry entitytrackerentry1 = (EntityTrackerEntry) iterator1.next();

                if (entitytrackerentry1.myEntity != entityplayermp) {
                    entitytrackerentry1.tryStartWachingThis(entityplayermp);
                }
            }
        }
    }

Which is called during the server tick loop
@ 588 updateTimeLightAndEntities(); (technically inside using @ 686 w/ worldserver.getEntityTracker().updateTrackedEntities(); )

Update entites are done through @ 674 worldserver.updateEntities(); which is where desapwning logic i.e. livingupdatevent would occur (which doesn't remove entities but marks for despawning naturally)

while my entity updates are done during the pre server tick before at
@ 577 FMLCommonHandler.instance().onPreServerTick();

Conclusion. Cannot see how am effecting this, Someone/something is messing with private Set trackedEntities = new HashSet(); and I cannot imagine why.

Also getting this error randomly. Server/client crash when it happens. Maybe their is a similarity in the mods me and op are using. In case op would like to post his also here is my base mod list.

http://paste.ubuntu.com/11567739/

I have a suspicion of which of my mods "could" be doing it as long as it is not an issue cause by using the iterator next() function. If there is any more help or info I can give please let me know. I can use my dev/mirror server to test it out if need be.

p.s. I have all chunk loaders disabled.

@skittishtrigger If you still experience this please provide a crash report / log. Some users tend to get the same header and assume the same error but it is caused by something else.

i.e. a different ConcurrentModificationException issue should be fixed http://www.minecraftforum.net/forums/mapping-and-modding/minecraft-mods/1288431-just-another-spawner-jas-v0-14?comment=2235