When teleporting the player during certain events, a ticking entity error is raised. This seems to happen during a few events I've noticed anecdotally, but a surefire example is given below.

Example
When the player is the victim of EntityDamageByEntityEvent (within which they don't die, and the event is cancelled) teleporting the player from (for example) the nether to the overworld will cause a "Removing entity while ticking!" error.

From discussions with md_5, this seems unintended, and potentially fixable in the World#teleport method.

Example stacktrace:

https://paste.md-5.net/azamotidif.nginx

Further errors also occur repeatedly as a result of this. The player becomes a "ghost" can't send messages/commands, can't interact with anyone or blocks.

https://paste.md-5.net/ezaxumejoz.bash

Additionally, a similar error seems to occur if the player is kicked in the event. Stacktraces can be provided if desired.