The error "This is not FreeArc archive or this archive corrupt" typically occurs during the installation of large software packages (often game repacks) that use the FreeArc compression algorithm. It indicates that the decompression tool (usually unarc.dll) cannot read the archive headers or find valid data, often due to system file corruption, hardware instability, or incomplete downloads. Common Causes
If it finds errors it can't fix, run: dism /online /cleanup-image /restorehealth. 2. Increase Virtual Memory (Paging File) The error "This is not FreeArc archive or
How to check:
Before doing anything else, check if the file really is a FreeArc archive. Use a hex editor or a simple text viewer. often due to system file corruption