Corrupted ISO. Delete the file, re-download from a different source, and ensure you extracted the full file (not just the preview).
Word count: ~1,450. Optimized for keywords: Fight Night Round 4, PPSSPP, highly compressed install, PPSSPP settings, ISO extraction, Android emulator boxing. fight night round 4 ppsspp highly compressed install
If you want to play a legitimate boxing game on your handheld or console, consider these options: Fight Night Round 3 (PSP) Corrupted ISO