Hello,
It seems you are running the .msi file from the Network drive:
Upon checking the logs, we found:
\\fbaserver\FOGA\DATOS\INFORMATICA FOGA\INFORMATICA FOGA\02 - Aplicaciones - Utilidades\1 - UTILIDADES SERVIDORES\SYMANTEC ENDPOINT PROTECTION 12.1.2\SEP_SBE_12.1.2_Part1_Installation_SL\SEPx64\Sep64.msi
I would suggest you to either use the setup file to be copied to the Local machine and then run the .msi file from the local machine.
OR
Deploy the package via Client Deployment Wizard, check this Article:
Client Deployment Wizard Overview
https://www-secure.symantec.com/connect/articles/client-deployment-wizard-overview
Hope that helps!!