Posting this so that it may help others.
A client performed Windows updates on an AWS server running Windows 2012 R2 today and afterwards found that the FileMaker server would not start with the error: FileMaker Server Helper quitting! Network initialization error. (CORBA::INITIALIZE)
It turned out to be the SSL certificate that was preventing it from starting. Removing the file serverCustom.pem from here: C:\Program Files\FileMaker\FileMaker Server\CStore allowed the service to start and access to the Admin Console was then possible.
After that I also removed serverKey.pem and serverRequest.pem. Then created a new SSL certificate request from within the Admin Console, re-keyed the SSL, reinstalled the re-keyed SSL and all seems well once again.
I can not explain why it happened but hopefully this helps anyone in a similar situation get back up and running quickly.
Started our AWS development server this AM and encountered the identical issue. Thanks for posting. You probably saved me some significant time trying to track the issue down.