Now for the part you came for. It's recommended to try these solutions in order, as they progress from the simplest and most common fixes to more advanced ones.
Error triggers immediately on system rigs with 8GB–16GB RAM. Step-by-Step Fixes for Unarc.dll Error Code 12 unarcdll error code 12 dodi repack
: Insufficient physical RAM or Virtual Memory (Page File) to handle the intense decompression process. Now for the part you came for
Here is a comprehensive guide to fixing this error and getting your game running. What Causes Error Code -12? Step-by-Step Fixes for Unarc
This error is notoriously frustrating because it usually pops up at 90% or higher during an installation. While the error claims the archive is "corrupted," the problem is often rooted in your system's environment rather than the game files themselves.
: Set your Windows Power Plan to "Balanced" rather than "High Performance" to help maintain stable temperatures.