Solution 1:

Symantec is the company who makes Norton Anti-Virus & also Symantec End-Point protection.

If you have another antivirus product on your Mac - Avast - then you should completely uninstall Norton &/or Symantec [Symantec may have been installed as part of a corporate package, in which case you'd need to check with the relevant IT department].

Having two live-scanning* antivirus products on one machine is bad - they can fight each other.

This doesn't include such as Malwarebytes Free, which does not live-scan.