Rasply

Can't seem to message you for some reason, so I'ma just tell you here, it's not a big deal. It's called LueraCraft Test Pack.

Just got off work, thanks for the reply. The modpack in question has an... odd history. It was originally a pack made for and by a specific server, and very tweaked and optimized. The guys who maintained it were masters of their craft, but, long story short, the server eventually closed. The aforementioned friend of mine decided to make his own server with this pack, and did so (with the makers' blessing) by copying the mods, configs and etc. from his client installation to a server one, then removing the client-only stuff. It actually worked well, and he later made a new pack based on it, with a bunch of additional mods. Now we have too many mods, and need to cut back a few to save performance. But, as mentioned in OP, removing mods shuffles all the IDs for some reason. Apologies for the history lesson, I just hope some insight can be gleaned from knowing how things got to this point. Anyway, to refine my original question; What kind of specific pack tweaks do you think could cause such a bizarre issue, and what could be done to resolve it?

So a friend of mine has been maintaining a custom modpack for a little while now, and on a few occasions he's had to remove mods from the pack. When he does so, he simply deletes the .jar from the Mods folder, tests it out, and updates the pack (I think). However, each time this happens, every single modded item/block ID gets swapped for something completely different, and we have to reset the world. I get that server wipes happen when you play with modded Minecraft, but I can't help feeling that this is a preventable issue. In fact I've seen it done before, without touching IDs, on other packs. But any searches I've done on the subject have led to threads about dealing with ID conflicts when adding mods So my question is, for future reference, how do you preserve existing item IDs after removing mods from a custom 1.7.10 pack? Any help or insight is welcome and will be relayed to my friend pronto, cause this pack is getting pretty laggy. P.S. If you really need to know what the pack is to help I'll PM you it when I get off work this evening so you can check it out, but right now I prefer not to advertise.