Zero.sievert.v0.26.2.zip ... - File:

To use the file, you need to extract its contents into your primary game directory. This specific version (v0.26.2) was an early early-access update that focused on critical bug fixes and quality-of-life improvements. Installation Guide

: Fixed a bug where it rained constantly in the Swamp and addressed a rare world-generation error for that map. File: ZERO.Sievert.v0.26.2.zip ...

Are you looking to this specific version, or are you trying to downgrade from a newer release? To use the file, you need to extract

: Copy your save files from %AppData%\Local\ZERO_Sievert to a safe location before proceeding. To use the file