Sometimes you may get an error in Sophos as "Virus Scan Failed: File Encrypted." The error can be defined by two meanings. First, Sophos is unable to scan encrypted or password-protected files. Second, other software cannot scan encrypted or password-protected files. Sometimes your Sophos software may encounter scan failures. Many times some conflicting software may also interfere.
This is the first step in troubleshooting the scan failed issue. You must install the latest version of Sophos software. To do this, visit Sophos's official website and move to the Downloads section and get the latest Sophos version. Then, install it on your system to fix the scan failed issue.
Sometimes, the existing running program or software may interfere with your current software. Hence, avoid keeping multiple programs on your PC; it will eventually interfere with your Sophos software. So, it's better to uninstall those.
In your Sophos software, check for the scan settings. This is to confirm that the settings are configured correctly.
Sometimes insufficient system resources may prevent your antivirus from scanning. Hence, check whether your computer device meets the system requirements to run Sophos properly. For instance, RAM, CPU, and disk space are considerable while installing software.
If nothing works out for you, consider reinstalling the Sophos software. It may fix your issue.