Disable auto re-assigning block ID's

I recently discovered that when I install mods that use Minecraft Forge, their block ID's are automatically reassigned by Minecraft Forge, and I ran into some issues with this feature. For example: When I update minecraft or for whatever other reason need to reinstall a mod, it reassigns block ID's again with other numbers then before. And when someone else installs the same mod they also get other ID's then I have. This creates map incompatibility, which can be very annoying.

I understand that this is probably meant to avoid ID conflicts, but somehow in this case it rather caused an ID conflict that wasn't there in the first place. I installed SimpleOres and Netherrocks, both made by AleXndrTheGr8st, and their default ID's are perfectly fine in not conflicting with eachother. However each time Minecraft Forge reassigns their ID's they do conflict on a large scale, rendering many items from one of them unavailable.

Therefore I would like to know if there is an option to disable auto reassiging ID's or if it would be possible to only reassign ID's when a conflict is found. Or even better, having Minecraft Forge ask what to do when it has found a conflict. I am currently running Minecraft v1.4.2 with Minecraft Forge Universal v6.0.1.349. I hope anybody can help me out with this, because I'd really like to be able to solve this!

Forge never re-assigns block or item ID's. It only auto-assigns a block or item ID when mod is creating a new config file. If Forge finds a block ID conflict with pre-existing configs, it will crash.

Okay, but in the case of these mods it auto assigns conflicting ID's while there are default ID's in the sourcecode that aren't conflicting with each other. How is it possible that these default ID's are skipped and conflicting ID's are assigned? Because using these defaults not only prevents conflicts, but also world compatibility issues. And I would think when auto assigning ID's Minecraft Forge would at least check if it has assigned the chosen ID's already, but maybe something went wrong here?

What are those defaults?

Check this post by the mod author for the default ID's: Click!

If you stick your old configs in your config folder then it'll load them just fine. Forge automatically re-assigns block ids that are requested below 255 to something above 256, to keep that area clean for terrain-gen blocks.

Speak with the mod author about this, he can easily change it so that it accepts ids < 256 for world gen. However, In the case of the mods you've specified none are terrain gen.

So ya, go yell at the mod author to shoose something > 256

I alerted the mod author to this topic, but I do want to add something here. You say it would be solved if those default ID's are above 256..... in fact most of those default ID's are above that, but still ALL ID's, including the ones higher then 256, get auto assigned by forge. So how is that possible if the problem is only the low ID numbers?

For blocks, the lower limit is 256, for items its 4096.

This is to keep the space free for what they really are.

IDs for blocks are 1-4096, Items are 4097-32000

Anything that asks for a default that is allocated to a different type {AE: A Item has a default below 4096, or a block has a default below 256} it'll be assigned a new one.

Se essentially, mod authors need to pick logical defaults.

Thank you very much, that makes everything clear! I have posted this link in the topic of one of these mods, so I hope that the mod author will read this and that he'll be able to solve the ID reassign and collision conflict with this!

The only question that remains on my mind is how it is possible that Minecraft Forge chooses conflicting ID's for these two mods, I would think that should be impossible? And as I read the mod-topics I am not the only one that had that happening?

It shouldnt be possible for it to pick conflicting mod ids if they both use the forge id system.

If you're mixing and matching, or the mod author is doing something stupid, then there may be issues.