Install the latest version of Java 1.8.
You may need to update the security settings to allow strong encryption and decryption of files.
For Java 1.8.0_151 and later, the "crypto.policy" Security property must be set to unlimited for the JRE used by PhixFlow. In the JRE directory /lib/security/java.security file alter the line:
# crypto.policy=unlimited
Uncomment this line (remove the "#") so it now reads:
crypto.policy=unlimited