Crash reports on another mod that builds its own tooltips, Parry This!, state a concurrent modification exception building tooltips that refer to its provided tags. Your mod is among other custom tooltip mods that crash in this fashion. I feel parry this is the core of the issue, such as not registering tags before renderers, but your mod is involved so I felt it best to include this here.

theishiopian/Parrying#21

I can confirm it is an incompatibility with your legendary tooltips mod.

I couldn't find any incompatibilities with Legendary Tooltips or Iceberg. I have however created a PR in Parry This that fixes this issue.