This has been in the for a long time, so I was surprised that I was unable to find an existing report.
When you exit any portal or the world loads when your computer is experiencing a large amount of lag, the game lets you fall. If you fall a short distance, it plays the "trip" sound, and a large distance playd the "fell" sound. This is especially true with a high render distance in the following conditions: exiting the nether to new chunks or to existing chunks with high cpu load (e.g. amplified), loading the end for the first time, entering an end gateway to leave the main island, entering the nether at all, or going really far out in the overworld using a nether portal (i.e. >10,000 blocks) this issue was really bad in 20w49a as every time I'd log in I'd fall into the void (without taking damage), but now in 20w51a it is just when the server can't keep up. It is only for me when I exit a nether portal that isn't within spawn chunks and the chunks aren't already loaded and with the end portal and end gateways.
(This is similar to the effect that occurs when you are on top of a glitched invisible block and you spam jump and then break the block.)
Note: You have to be in survival mode to replicate this.
Linked issues
is duplicated by 3
Comments 12
When the player has entered a Nether portal and is arriving in the other dimension, the player initially falls through the world until terrain loads, and is then teleported to the correct location. When the player is teleported to the correct location, the sound plays. This falling can be clearly seen if the debug screen (F3) is active.
It appears that the player is being placed into the world before the terrain around the player has finished loading. The terrain should be loaded first, and then the player placed into the world. It is not necessary to load all of the hundreds of chunks around the player before placing the player. It is only necessary to load the chunk the player is in, and the surrounding eight chunks (the extra eight chunks are intended to cater for players arriving at a chunk boundary).
Some code analysis would be helpful here, to clarify what is happening.
Can confirm in 1.17.1 Release Candidate 1. Sometimes this happens even when the world isn't lagging, and sometimes it only happens when changing dimensions, not when the world is initially loaded (MC-230890).
Affects 1.17. May be related to MC-23.
This usually happens whenever the game loads or the player enters or leaves the Nether with a portal. The subtitles read "Something tripped" or "Something fell".