This specific error usually points to an issue with memory (RAM) or the archiving software (like WinRAR or 7-Zip) used to compress the installer. It can also be triggered by a lack of disk space, security software blocking the extraction, or corrupted installation files. Step-by-Step Solutions 1. Disable Antivirus and Windows Defender
When you see "unarc.dll returned an error code 1", it means the decompression process stopped unexpectedly. Error code 1 is a general failure indicating: how to fix unarc dll returned an error code 1
Q: Can I ignore unarc.dll and just delete it?
A: No. The installer will not run without it. You must fix the underlying cause. This specific error usually points to an issue