If you are trying to extract a game, a large software installation, or a compressed dataset and are met with the error message "This is not FreeArc archive or this archive is corrupt," you are likely dealing with a file compatibility issue or a bad download.
FreeArc is a popular compression format used frequently for repacking PC games due to its high compression ratio. However, because it is less common than ZIP or RAR, users often run into trouble opening these files.
This guide will walk you through the causes and provide step-by-step solutions to fix the error and recover your data.
If you are installing a game repack and get this error:
Setup.exe and a small file named Setup-1.bin, Setup-2.bin, etc.unarc.dll in the folder, the installer uses FreeArc.FreeArc is excellent but no longer actively maintained. Newer tools sometimes ignore minor header corruption.
Try these alternatives:
.arc file → 7-Zip → "Open archive". If it opens, simply extract. 7-Zip handles more variations than FreeArc GUI.unarc.exe yourfile.arc| Error displayed | Likely issue | Next step | |----------------|--------------|------------| | “This is not a FreeArc archive” | File is wrong format | Check file type with hex viewer | | “This archive is corrupt” | Data damaged or incomplete | Re-download, check size, test checksum | | Corrupt link (in context of this error) | Download incomplete or source file bad | Re-download with resume; find mirror |
While standard 7-Zip struggles with FreeArc, there are modified versions or plugins that can help if the official FreeArc tool fails.