FerriteCore causes network protocol errors when trying to join servers if Lithium is not installed/enabled
Closed this issue · 2 comments
Hello!
I was manually testing enabling and disabling the mods I have installed to discover the root cause of an unrelated problem, and I noticed that, when I have FerriteCore enabled, but not Lithium, I'm not able to join any server. I tried with my private SMP server running on Fabric and with Hypixel, both returned a network protocol error. Is Lithium a dependency of FerriteCore?
Logs are attached below.
minecraft-log.txt
disconnect-2025-11-01_12.37.38-client.txt
disconnect-2025-11-01_12.37.42-client.txt
I will look into this, it looks like disabling useSmallThreadingDetector should fix it for now. Litium contains a different optimization for this code1, so FC automatically disables the option when Lithium is present. That's why it looks like installing Lithium "fixes" the problem.
Footnotes
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Lithium's optimization is more powerful (saves more memory), but does not satisfy FerriteCore's stronger requirements on equivalent code behavior. In vanilla (or with non-buggy mods), Lithium's implementation is equivalent, but it hides a specific (rare) type of bug. ↩