What is Minecraft Bedrock Error 422 and why does it occur?

Minecraft Bedrock Error 422, often referred to as 'Unprocessable Entity,' typically arises when a modpack or resource pack contains invalid or corrupted data that the game client cannot process. This can be due to incorrect JSON formatting, incompatible mod versions, or conflicts between mods. It's frequently linked to issues with the modpack's manifest file or individual mod files.