This is a silent killer. If you are installing to a USB drive, old external HDD, or a partition formatted as , you will get Error Code 1 without fail.
The message typically appears during the installation or unpacking of large files, especially highly compressed game "repacks". This error signifies a failure in the decompression process, often caused by insufficient RAM , disk space , or corrupted archive files . Primary Troubleshooting Steps how to fix unarc dll returned an error code 1
Large LZX streams may require extended virtual memory. This is a silent killer