«Ticking entity» crashes and how to remove the culprit

What you are seeing

• Exception ticking entity or Exception ticking block entity in the crash report.
• The server crashes moments after starting, every time.
• It only crashes when a specific player joins, or when someone goes to a specific place.
• The crash report includes an entity type and a block position.

Reading the crash report

1. Find the entity type and coordinates

   The report includes an «Entity being ticked» or «Block entity being ticked» section with the type, its position and its world. That is exactly what has to go.

2. Write down the coordinates before you do anything

   They are the whole answer, and they are easy to lose in the next restart's output.

3. Take a backup

   You are about to edit the world to remove something. If the wrong thing goes, this is the way back.

Removing it

1. If the server stays up long enough, do it in game

   Fly to the coordinates and remove the entity or break the block. This is the easiest case and it works more often than people expect.

2. If it crashes too fast, stop it loading

   Move the player's .dat out of playerdata if it crashes on their join, so the server does not load their location at startup.

3. Otherwise use an offline region editor

   A tool that opens region files can delete a single entity or a single chunk without the server running. Deleting the chunk regenerates that terrain and is the heavier option.

4. Start and watch

   If it survives past the point it used to die, you removed the right thing.