Hello, I am running Create as part of the Slightly Vanilla Flavoured modpack on both Forge server and client. however, on my forge server, create:zinc_ore and create:copper_ore don't register properly. (i'm not exactly sure what this means but i can provide the exact error report if necessary) Everything seems to run fine on my client, which is running every mod that the server is running.

This was much easier to find than it could have been because the modpack comes with Blame 1.7.6, which helps to register any unregistered features. However, i am not entirely sure if this error would have been fatal without Blame, or whether it would cause zinc and copper ore not to generate in the world. This may be possible, because the unregistered feature seemed to specifically have something to do with natural ore generation. Anyway, it seems to be okay for me (knock on wood) and i am sharing purely for the benefit of others.

This issue has been marked as stale because it has been inactive for 3 weeks. It will be closed if it remains inactive for another 3 weeks.

This issue has been closed since it has been inactive for 3 weeks since it was marked as stale.

Can you get Copper and Zinc ingame? I have a server running create 1.16.3_v0.3c and it works, mabye list your mods?

Oh i forgot to mention i am running Create 1.16.3 v0.3b with Java 11, LWJGL 3.2.2, Forge 35.1.29, Slightly Vanilla 1.0.1, and Minecraft 1.16.4 My operating system is Linux Mint 20.0.4 (64-bit) and i use MultiMC 5 to launch my client. If it helps to know, Slightly vanilla does have a few mods that affect sub-surface generation.
More comprehensive mod list here (in changelog)
I also have optifine on my client.

Yes, i can get copper and zinc ore from the creative menu while on my client, but as i said the client boots without issue, and even if it also works on the server, it may be solely because my modpack happens to include Blame to patch things like that

How did you even get it to run on a server? It doesn't work for me with the latest version.
Also, step one in mod troubleshooting is to get rid of optifine.

This is a duplicate of #539.

And it can absolutely break other mods, and will do so silently. An example of such is MatrexsVigil/phc2trees#27 where unregistered trees in one mod completely nukes all vegetation grown in an entire dimension in another mod. This is on the drastic end of examples, but it demonstrates how Create may currently be breaking other mods' features right now and people don't even know.