Before fixing, know the enemy:

Antivirus software often mistakes compressed installer files (especially for games or cracked software) as malware and blocks specific files from being unpacked. This results in a "corrupted archive" message.

Inno Setup (which powers ISDone/Unarc) has a known bug: it hates non-English characters in file paths. If your Windows username contains accented letters, Cyrillic, or Chinese characters, the temp decompression path becomes corrupted.