Describe the bug

After trading with a Villager that trades Emeralds --> Bones & letting his trades refresh all trades get disabled/removed & an error message appears at the top right side of the screen.

To Reproduce
Steps to reproduce the behavior:

• Find a Villager that trades Emeralds --> Bones.
• Trade anything with him.
• Exit out of the trading UI to let his trades refresh.
• Try trading with him again.

Expected behavior

Expected more trades to appear instead of all of them to disappear.

Screenshots

Info (please complete the following information):

• Modpack Version: v2.77.5
• Server or Singleplayer: Singleplayer
• Version the world was created on: v2.77.5

Additional context

Crash Report: https://pastebin.com/iT18HgRj

Reopen issue if this still occurs in 3.0 beta 4 or later. its probably fixed