unknown_file.jar
by Trevol010
unknown_file.jar is a NeoForge 1.21.1 mod by Trevol010 that adds joke-style world features, including erasing and banning worlds and opening popup windows.
What it does
Installed on a client or a server, the jar brings a set of cursed features that alter how worlds and the game interface behave. Its author notes describe erasing worlds, banning worlds and creating popups, and the mod also includes textures inspired by the Alpha and Classic eras and a testing set for hunger mechanics from the Modern Beta period.
The mod also carries some assets drawn from Scott Cawthon's games, which the author notes say may change in future versions. Runs on NeoForge only, for 1.21.1, with the latest file 0.1.8 published on 2026-06-03 in the beta channel. Released under the Creative Commons Attribution Non Commercial 4.0 license, so the code is not open source. The mod was first published on 2026-02-10 and last updated on 2026-06-03.
Both the server and every player need the jar, since the environment is client and server. Trevol010 lists the mod under Cursed, with Adventure and World generation as secondary categories. Other NeoForge mods for 1.21.1 are also listed on the catalog, and this one is in the same loader and version range.
Key features
Erase worlds
A feature that removes worlds from the save list, intended as a joke on the cursed category.
Ban worlds
Worlds can be banned, blocking players from entering them once the feature is triggered.
Popup windows
The mod can create popup windows that appear over the game screen.
Alpha and Classic textures
The Golden Days Alpha textures restyle parts of the game in the look of early Alpha and Classic versions.
Modern Beta hunger testing
A testing set for hunger mechanics, modeled on the Modern Beta period.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Questions
Does unknown_file.jar need to be installed on the server?
Which loader and game version does the mod support?
In the catalog
unknown_file.jar is one of 7,555 Cursed mods on ModsFinder, and one of 2,801 Cursed mods for NeoForge. 32,366 mods support Minecraft 1.21.1.
Similar mods
What the author says
-MOD IS BEING REWORKED, PLEASE CHECK THE DISCORD FOR MORE INFIRMATION- unknown_file.jar is a RANDOM progression horror mod that slowly corrupts your world (it isn't really slow lmao), while you uncover the secrets of its dark past. This mod sends you back to the alpha versions of minecraft, but things feel really…
Official listing
- Modrinth page
- modrinth.com/mod/unknown_file.jar
- Owner
- Trevol010
- Published
- 2026-02-10
- Updated on Modrinth
- 2026-06-03
- Facts verified
- 2026-10-15
