How to read a minecraft log?

[DragonITA]

Hi, i have see a lot of users that have start its game, then it has stop and its received a great (crash) log, not only these users but i self included. So, when i am getting a crash, i try to read its log, but i never full understand where i should see… Can here explain how logs to read logs, a sort of mini-tutorial? Pls.

[loordgek]

post the log

[DragonITA]

No, i mean this in general. Here was a method to read any sort of log, or not? This is my question. I yet not have a problem (outside from my entity problem that the stream was empty, no, i not have any problem). But thanks for replying.

 

[loordgek]

can you a random log so i can explain it

[DragonITA]

Ok

[DragonITA]

@loordgek this is a example: https://github.com/DragonGamerDevelopers/Minecraft-Modding-Logs/blob/master/crash-2020-02-14_23.00.49-client.txt This is a old crashlog that i resolved.

[Ugdhar]

So this is how I am reading that log you linked:

1. I notice it's a Null Pointer Exception (NPE), so something that's null is being accessed

2. Not much more information at the top here, just a list of classes where it errored out, but I don't believe that it was the actual AgeableModel that is crashing us, so I continue scrolling/scanning the log

3. Further down, we see some stuff about a unicorn, so to me, that's where I'd be looking.

 

Of course, you only posted the crash log, no debug, so info is limited, and no code to go with the crash. But basically, scan through it (you have to be patient, and actually LOOK at everything, at least a little) and look for stuff that is:

A) understandable, i.e. looking for "exception caused by" or something like that;

B) any class/package names that are from your project, as these are most likely to cause the issues.

 

Honestly, it's really just programming experience and practice that make a programmer able to debug their stuff. The more you are exposed to it, the more you will understand. Something confusing now, if you keep with it, and continue to learn/grow, in a month you'll look at the same confusing thing and find it much easier to understand. If you find something too hard, back off a bit, work with something a little easier, then come back to it later with a clear mind and maybe a little more knowledge.

[DragonITA]

1 minute ago, Ugdhar said:

1. I notice it's a Null Pointer Exception (NPE), so something that's null is being accessed

Whats Line?

1 minute ago, Ugdhar said:

3. Further down, we see some stuff about a unicorn, so to me, that's where I'd be looking.

Thanks

 

I not have ask for help with my problem (i already resolved this), but on how to read in general all type of log. Thanks, now i know a little more on how to attempt this.

[Ugdhar]

1 minute ago, DragonITA said:

4 minutes ago, Ugdhar said:

1. I notice it's a Null Pointer Exception (NPE), so something that's null is being accessed

Whats Line?

Quote

java.lang.NullPointerException: Rendering entity in world

at net.minecraft.client.renderer.entity.model.AgeableModel.func_225598_a_(SourceFile:62) ~[forge-1.15.2-31.1.0_mapped_snapshot_20190719-1.14.3.jar:?] {re:classloading,pl:runtimedistcleaner:A}

Not sure if that's the line number or not where it says "SourceFile:62", but again, probably would want to look at the debug log, not just the crashlog (I know this is old, but if it were new that's what you'd want to do) for more info, as it may be crashing in that method in AgeableModel, but it's more than likely not CAUSED by the AgeableModel.

[DragonITA]

Yes, if i remember good, then it was a problem with the spawn egg, but i just look how Cadiboo has done and i resolved it or it was another Problem.

[DragonITA]

Ok, but here is a user that has ask for help with a server log, and it see different as the normal logs. Does this was normal (not need to understand the log, but only want to know if mod and server logs are different)?