As seen in the EVInstall log:
6-2-2018: 11:01:35: Enterprise Vault Indexing Msi Return Code: 1619
6-2-2018: 11:01:35: ERROR: Could not install Enterprise Vault Indexing Msi
6-2-2018: 11:01:35: DialogShowError Begin
No specific error in the event logs
Missing permissions on the EV temp directory
Internal notes:
>>Customer getting error "ERROR: There has been an error installing the Enterprise Vault Indexing components." during an upgrade from 11.0.1 to 12.3 on a windows server 2012 machine.