After a fresh installation, Endpoint Protection user interface (UI) has a warning with error "Firewall malfunctions". These errors have been observed in the system logs as well. 

On opening the SEP (Symantec Endpoint Protection) UI shows "Firewall is not functioning correctly. Your protection definitions may be damaged or your product installation may be corrupt”

Follow below steps to resolve the issue:-

1. Stop the SEP services by running the below command from the Run prompt.
   1. smc - stop.
2. Navigate to Open Network and Sharing center.
3. Select the Network connection and right click properties of Local area connection (NIC adapter).
4. Click Install and select 'Service' and then click 'Add'.
5. Click 'Have Disk' and browse to "Symantec install path">C:\Program Files (x86)\Symantec\Symantec Endpoint Protection\12.1.7061.6600.105\Bin64\TeeferWin8.
6. Based on the OS, select 'teefer.inf' file from following folder and install.
7. Reboot machine.