Problem

Axway Installer can not install any patch for 5.3.X, failing at a very early stage with the error:

Initialization in progress
......
A fatal error has occurred while updating
Reason: An internal error prevented Axway Installer from continuing:
null
An error has occured and Installer process will exit.

The install.log does not provide much details as well. The most essential part is shown below:

2017-07-06 11:36:00 DEBUG LOADING VARIABLES FROM FILENAME: (fullFileName=/opt/Axway/Configuration/Install_Axway_Installer_V4.8.0.properties, overwrite=false)
2017-07-06 11:36:00 DEBUG LOADING VARIABLES FROM FILENAME: (fullFileName=/opt/Axway/Configuration/Install_SecureTransport_V5.3.6.properties, overwrite=false)
2017-07-06 11:36:00 FATAL An internal error prevented Axway Installer from continuing:
null
An internal error prevented Axway Installer from continuing:
null
at com.axway.synchronyInstaller.engine.SynMain.main(SynMain.java:199)
Caused by: java.lang.NullPointerException
at java.io.File.<init>(Unknown Source)
...

Resolution

In some rare situations, a new installation of ST without specifying a secret file (which is the default behavior of the installer) leads to a problematic combination of two parameters (see below) in the Install_SecureTransport_V5.3.X.properties file.

Problematic combination

SecretFilePath = 
SecretFilePath.Type = File

During consequent patch deployment for ST 5.3.x, this combination leads to the Axway Installer failing with the error shown above. To resolve this, remove the second parameter SecretFilePath.Type = File from the following files:

<Axway Home>/Configuration/Install_SecureTransport_V5.3.X.properties 
<Axway Home>/SilentFile/YYYY_mm_DD_HH_MM_SS_install/Install_SecureTransport_V5.3.X.properties

Save the files and re-run the upgrade.