Why am i crashing?

[Narc]

Can i provide some other info about the crash to help figure out the issue?
Are there more logs somewhere?
Alone i wont be able to fix this and the support page have not answered.

The problem is that this error is perfectly generic -- unless someone notices a mod known for causing this error, they won't be able to help.

However:

• the error is a concurrent modification (someone modified a hashmap at the same time someone else was iterating it)
• this generally happens when multiple threads are involved (one thread alters the hashmap while another thread is iterating it)
• almost none of the mods you have do anything that would involve multi-threading, except...
• Zan's Minimap probably has a separate thread on which it generates its map.

So I posit the following possibility:

• Zan's reads the world chunks in one thread
• Minecraft receives new chunks in another thread (the main thread, in fact) and writes them to its client-side cache

Result: explosion.

Try replacing Zan's with MapWriter or JourneyMap and see if it stops derping.

Edit: That said, this should be a more common error if it's really Zan's Minimap causing it -- lots of folks run that and Mystcraft together. I think.

 

[belgabor]

Edit: That said, this should be a more common error if it's really Zan's Minimap causing it -- lots of folks run that and Mystcraft together. I think.

While true, the same holds true for the error I had (crashlog pretty much identical, only Packet51 instead of Packet56). Took me ages to find the culprit, would never have suspected Zan's if I hadn't found a post saying to try to remove it. Even then I couldn't believe it until the error stopped once I did.

It could well be some kind of mod interaction that causes it, even some subtle world corruption or coincidence that triggers it when Zan's is active, so I even hesitate to call Zan's the culprit. But in my case it was certainly a factor that, once removed, prevents it from happening.

I'd like to note that in the case of my error there was no deterministic cause, it happened now and then randomly out of the blue.

 

[Narc]

While true, the same holds true for the error I had (crashlog pretty much identical, only Packet51 instead of Packet56). Took me ages to find the culprit, would never have suspected Zan's if I hadn't found a post saying to try to remove it. Even then I couldn't believe it until the error stopped once I did.[...]

By "common", I referred more to number of people reporting it than to number of occurrences for one person.

In your case, Packet 51 (a single map chunk) versus Packet 56 (a block of chunks) both seem very similar errors to me -- it may be that
Zan's used to cause issues in one variant and now causes them in the other. It also may only happen on a specific CPU architecture, specific versions of the Java virtual machine, and other factors, all of which come into play when debugging multi-threading issues, and which may lower the reporting rate of the same issue.

So, yeah, could go either way.

 

[behedwin]

Okey

I have now disabled Zensmap mod and replaced it with one of the other options.

I have played for over an hour and activly used portals (bit extra much) and have not crashed once.

It looks like the map mod was the issue.... but i wont say YAAY just yet... but looks good so far