After the 26.0 update, I updated my game and was testing a laggy minigame which used lots of entities, and commands to make them angry at each other. I had my computer connected through LAN to test, and began to notice that the game was very laggy. I tried to move my horde of zombies at the computer’s horde (a total of 80-120 entities roughly I think), however the game crashed. This wasn’t unusual for this minigame due to the number of entities and the commands constantly running on them, and I had been working to reduce the lag, however once trying to load back into the world it crashed again. After trying several times to enter the world, and also trying to deactivate and reactivate the add ons in the world (two very basic add ons I made myself, one with 2 lag reducing functions for a different minigame and one with the simplest entity I could create as a marker). I then tried moving a copy of the world file to my computer and changing it to a .mcworld file, but it failed to download, which is why I am concluding that the world was corrupted.
I have backups for this world, so I only lost a couple of days of progress, but there are multiple laggy minigames in the world, and I have known 2 instances of crashing in the world without any lag at all before the update. Some change in the recent update seems to have made crashes cause corruption, which is a serious problem. Overall, bedrock needs to handle RAM usage better (which I am pretty sure is the reason for crashes when running laggy things, RAM continues to fill until full, then Minecraft crashes) (implement systems to detect being low on RAM and lower RAM usage) and if Minecraft does crash, it shouldn’t corrupt the world, as for some reason it did in this update.
.mcworld file attached, a Minecraft file viewing program likely required as this file doesn’t seem to download properly:
Update: I tried to replicate the crash in a different world, but was unable to get the game to crash, suggesting either the process is specific, requires multiplayer (I will try this later), or it inconsistent and random.