If an entity is killed whilst receiving an event from another entity (i.e. with the minecraft:send_event component), the game will crash upon trying to remove the entity from the world - after the entity flashes red and falls over.
A world including a demonstrative behavior pack is attached. Running the command /kill @e[type=cow] will recreate the issue.
Thank you for your report!
Crashes such as these are logged automatically, and will be looked into further by the development team.
If you need help or support you might like to follow a link below.
Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Feedback – 📖 Game Wiki