Can I increase the maximum Forge/Vanilla ID limit, or remove it entirely? [closed]
Solution 1:
Minecraft actually allows item IDs up to 32767, but I believe block IDs only go up to 4096. You have a mod that is trying to add a block with ID 9884 - which is greater than the maximum block ID.
You might need to install another Forge mod like this one that extends the possible block IDs up.