If "MO2" refers to Mod Organizer 2’s internal format: Older versions of MO2 (pre-2.4) used a different compression method for downloads than newer versions. Trying to extract a mod created with MO2 v2.5 using MO2 v2.3 can throw an "extraction failed 7" error because the decompression algorithm doesn't recognize the header.
How many do you currently have on the drive where your mods are stored? extraction failed 7 mo2
Your Antivirus is "locking" the file as it’s being extracted. Step 1: Check for Archive Corruption If "MO2" refers to Mod Organizer 2’s internal