When apex is installed and tested as explained in the documentation, the following exception is issued.
 
[2020-08-18T15:29:03.082+00:00|ERROR|ApexMain|main] Arguments validation failed.
org.onap.policy.apex.model.basicmodel.concepts.ApexException: relative file root "/opt/app/policy/apex-pdp-package-full-2.4.0" does not exist or is not a directory
at org.onap.policy.apex.service.engine.main.ApexCommandLineArguments.validateRelativeFileRoot(ApexCommandLineArguments.java:353)
at org.onap.policy.apex.service.engine.main.ApexCommandLineArguments.validate(ApexCommandLineArguments.java:189)
at org.onap.policy.apex.service.engine.main.ApexMain.populateApexParameters(ApexMain.java:212)
at org.onap.policy.apex.service.engine.main.ApexMain.<init>(ApexMain.java:77)
at org.onap.policy.apex.service.engine.main.ApexMain.main(ApexMain.java:324)
[2020-08-18T15:29:03.082+00:00|ERROR|ApexMain|main] start of Apex service failed
org.onap.policy.apex.model.basicmodel.concepts.ApexException: Arguments validation failed.
at org.onap.policy.apex.service.engine.main.ApexMain.populateApexParameters(ApexMain.java:215)
at org.onap.policy.apex.service.engine.main.ApexMain.<init>(ApexMain.java:77)
at org.onap.policy.apex.service.engine.main.ApexMain.main(ApexMain.java:324)
Caused by: org.onap.policy.apex.model.basicmodel.concepts.ApexException: relative file root "/opt/app/policy/apex-pdp-package-full-2.4.0" does not exist or is not a directory
at org.onap.policy.apex.service.engine.main.ApexCommandLineArguments.validateRelativeFileRoot(ApexCommandLineArguments.java:353)
at org.onap.policy.apex.service.engine.main.ApexCommandLineArguments.validate(ApexCommandLineArguments.java:189)
at org.onap.policy.apex.service.engine.main.ApexMain.populateApexParameters(ApexMain.java:212)
... 2 common frames omitted