Recently updated Vault Hunters modpack, which including upgrading Supplementaries to 0.18.0. After upgrading I can no longer connect to my server. I see following crash log, which includes an issue with Supplementaries.
crash-2022-01-12_10.20.40-client.txt

Also posted on Vault Hunters Issue Page, not sure where the issue lies.
Iskallia/Vault-public-S1#674

I think I found the issue. I had not deleted the old 'mods' folder when updating to the new version, so both versions of each mod were in the folder.