Antivirus programs often see a program (MO2) rapidly creating thousands of small files (the mod) and mistake it for ransomware behavior. It "locks" the folder to protect you, which causes the extraction to fail.
If you are installing a mod and receive an error window titled with the code (7) , it indicates that Mod Organizer 2 has encountered a Data Error (CRC Mismatch) . extraction failed 7 mo2
Make sure you're using the latest version of MO2. The developers frequently release updates that fix bugs and improve performance. Antivirus programs often see a program (MO2) rapidly