The Symantec Endpoint Protection (SEP) installer or other Symantec tools fail to run on macOS 10.12 "Sierra" or later.
You may see one of the following errors:
See Additional Information for a full list of related errors.
These errors may be caused by a macOS security feature that assigns extended attributes ("com.apple.quarantine") to any file that has been downloaded from a network site or has been moved from its original download location ("App Translocation").
Other circumstances may have altered macOS file attributes or permissions settings.
Possible causes of these symptoms:
Reset the extended attributes and permission settings for the affected files.
For example, for "Symantec Endpoint Protection Installer" and "Additional Resources" in "SEP" folder of the user's desktop, open a Terminal window and run the following commands:
sudo xattr -rc "~/Desktop/SEP"
sudo chmod -R 755 "~/Desktop/SEP"
Next, retry the installer or tool.
Note: If the above path syntax does not work, try using the "cd" command to navigate to the appropriate parent folder (remove quotes for folder names that do not contain spaces) before trying the commands.
sudo xattr -rc <parent folder name>
See the full list of potential errors below: