oops-1.12-2.5.jar is a release file of the Minecraft mod Oops! - Undo, made for Minecraft 1.12.2. It was published on October 16, 2017 and is 0.1 MB in size. For the full description, screenshots and every other version, visit the Oops! - Undo mod page.
How to install: Put the .jar into the mods folder (.minecraft/mods) and start Minecraft with the matching mod loader profile.