Crash dupe

Crash dupe is a dupe that can be performed when the server crashes.

It was discovered by Ecchou, it works because of player data being saved more frequently than container data (Chests, furnaces, etc.).

This sync issue beetween container data and player data can be exploited by taking items from a chest to your inventory right when the server is about to crash.

If done with the correct timing and luck, the chest's items will have been saved before the crash, then the player data, and then the server stops without having time to update the container data, which results into the items being both in the chest and the player's inventory.

Events
Ecchou tried doing it once on the daily server restart on May 5th, 2020, however, restarts are different from crashes, because restarts automatically kick players seconds before restarting, thus eliminating any possibility of duplication.

However, about a month later (June 1st, 2020), JustAnotherSheep and Ecchou accidentally performed the dupe when Ecchou was travelling with fast flight hacks, the server was at peak hour, and the stress of the player count and fast chunkloading crashed the server. Right when the server crashed, JustAnotherSheep looted an end city chest. When the server was back up, the items were in JustAnotherSheep's inventory and in the chest.

Ecchou and JustAnotherSheep kept trying to make the dupe work again, however, after crashing the server about 7 times, Penguin4215 took action, and ended up patching the Timer hack, putting the June movement restrictions into place.

The crash dupe is still not patched, however, currently, it is next to impossible to crash the server, due to server hardware upgrades and the server itself running on an optimised .jar file (Paper Spigot).

The Crash dupe has been done on Purity Vanilla aswell, Penguin4215 and Boone's vanilla anarchy server, so it quite certainly still works, however, according to some sources, crashing Purity was done by breaking a double chest full of player heads that were obtained thanks to a plugin, so this crash exploit is impossible to do on TVE.

Here is a quote from JustAnotherSheep about when he performed the dupe:

"On June 1st, I worked together with Ecchou to dupe items for the first known time on TVE. He would crash the server using insane movement exploits, and I would take items out of chests with precise timing. You could argue that the constant crashing was largely responsible for the timer patch Penguin would later implement, and later the massive wave of old players quitting. Basically, Ecchou and I may be responsible for TVE sort of dying..."