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I've seen other questions referring to the same area of Minecraft mods but they're always asking for two mods compatibility or not being specific.

I have no experience whatsoever in Minecraft coding (texturing only), but I do know that when two or more mods aren't compatible that it's usually caused by one (or more) files are over lapping.

My question is, can I rename those files safely and simply with out corrupting the rest of the mod or my Minecraft installation? If not, is there another solution? This is NOT the case of having two mods of similar functionality.

--- BEGIN ERROR REPORT 2c7ee87f --------
Generated 7/19/12 6:23 PM

Minecraft: Minecraft 1.2.5
OS: Windows 7 (x86) version 6.1
Java: 1.6.0_30, Sun Microsystems Inc.
VM: Java HotSpot(TM) Client VM (mixed mode), Sun Microsystems Inc.
LWJGL: 2.4.2
OpenGL: ATI Radeon HD 4550 version 3.2.9606 Compatibility Profile Context, ATI Technologies Inc.

java.lang.IllegalArgumentException: Slot 234 is already occupied by JAMMY780.blocks.JAMMY780_BlockKitchenCupboardNoTop@29ea31 when adding MCA_BlockTombstone@1ce663c
    at pb.<init>(Block.java:249)
    at agy.<init>(BlockContainer.java:7)
    at MCA_BlockTombstone.<init>(MCA_BlockTombstone.java:36)
    at mod_MCA.load(mod_MCA.java:316)
    at ModLoader.init(ModLoader.java:891)
    at ModLoader.addAllRenderers(ModLoader.java:189)
    at ahu.<init>(ahu.java:77)
    at ahu.<clinit>(ahu.java:8)
    at net.minecraft.client.Minecraft.a(Minecraft.java:394)
    at net.minecraft.client.Minecraft.run(Minecraft.java:732)
    at java.lang.Thread.run(Unknown Source)
--- END ERROR REPORT c3b08de9 ----------
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Shouldn't this go into game development or programming.SE? –  Ender Jul 19 '12 at 7:32
Idk, never actually been on this website. –  Jake Jul 19 '12 at 8:00
the comment I made was more of a 'plea' to the rest of the community as to their opinions. however, as a newcomer, I would encourage you to read our FAQ to learn which questions are 'on topic' and generally just brush up on how we do things here. Welcome to ArQAde! –  Ender Jul 19 '12 at 8:34
Voted to close because it's impossible to really answer this question. You can't make any mod cooperate with any other mod, especially if they do similar things. –  dbemerlin Jul 19 '12 at 8:41
Abou h only thing you can do is complain at the mod evs. –  Zoredache Jul 19 '12 at 15:32

5 Answers 5

up vote 0 down vote accepted

My question is, can I rename those files safely and simply with out corrupting the rest of the mod or my Minecraft installation? If not, is there another solution?" To put it simply, no. The files refer to each other by name renaming it would crash the game because if the file is not found there is no way to continue without it.

If you know java you could open up mcp and rename the files and the references to them and if it modified a file that was built into Minecraft you would have to merge the code from both files.

But you said you don't know java in which case you'd have to see if someone has already merged those mods.

An other thing to remember is that mods are normally not compatible with each other because they have the same functionality. If that's the case you should just pick the best. Or maybe even a whole new mod that does what you want.

The last possibility is that they have the same ID for something in that case the mod might have a config where you can change IDs. I hope you get this figured out :-)

EDIT: judging from the error report, it looks like you will need to decompile the code and edit Block.java on 249 to change the ID. Then you need to recompile it

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The problem is with the same ID, doesn't mean I know how to change it though lol. Some reason everyone (excluding you), have a legitiment answer but they refer that the mods are simply the same thing. .-. Thanks for your answer! –  Jake Jul 19 '12 at 17:44
No problem. Also make sure you accept the best answer and read the FAQ if you haven't already :) –  Aidan Mueller Jul 19 '12 at 17:48
One more thing if I may, since you know what your talking about actually >.< With this Java decompiler, is it possible to decompile both of the files with the same ID and then recompile them into one .class file? –  Jake Jul 19 '12 at 23:07
Do you mean for overlapping files? Like both of them change example.class? Or do you mean for two mods with the same ID? If they're using modloader they most likely have the IDs defined in a class the mod added instead of editing a pre existing file. If its the IDs then check the config first. If there isn't one you could just open the file where the block or item is added and change the ID. –  Aidan Mueller Jul 19 '12 at 23:52
I appreciate this a lot, thanks!.....know any good decompilers >.< –  Jake Jul 20 '12 at 0:24

I'm not an expert, but there are many reasons why a mod might be incompatible with another mod. File overlap is one reason. Incompatible changes to the same game mechanics might be another reason - imagine installing Minecart Mania at the same time as Railcraft. Both modify the behaviour of minecart rails - the results could be very strange.

Renaming the mod files will, at best, result in errors due to the mods trying to find the contents of a file that doesn't exist (or more bizarre effects.) I would not recommend trying this.

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The problem is that there really is no support for mods in vanilla Minecraft. Existing mods are all literally just game hacks - they modify core Minecraft class-files to cause them to do something different. If there two mods modify the same core-file, then you are out of luck, unless you take the time to understand the modifications made by both mods, and manually merge them (you'll need a java decompiler like JD, and have to sift through mounds of obfuscated code).

However, there have been efforts to create a more consistent API to allow mods to work together. The most prominent is Forge API - mods using Forge should be mostly compatible with one-another. Bukkit also has its own API for server-side-only stuff. And of course, Mojang has been promising an official API for forever. When that happens, all other APIs will (hopefully!) become obsolete.

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Yay lol, thanks for the feed back :b –  Jake Jul 19 '12 at 23:11

Hmm. I once tried to get some Market mod in the Minecraft Single, and it needed many other mods to get working.

Hah, it didn't work, since it crashed about in the half way.

Naybe you could try to install one mod at the time and check, does MC work between installments. When/If after an installed mod MC stops working, remember to take info of both Mod and Computer and how/when it failed, when you start discussing about this with someone. It will help.

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Here's the thing... that can be fixed with NO FILE CHANGES WHATSOEVER! It's an ID CONFLICT! Look in the config folder, and some (if not all) mods should have a config file (open it with notepad) and change the id's to compatible id's. It's an annoying thing with tons of mods (try technic pack), but it's easy (ish) to do.

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