TIBCO ActiveMatrix BPM 4.x.x to 4.3.0 upgrade fails as appdev component fails to start. This failure occurs after the system AMX BPM application, commonly known as amx.bpm.app, has been upgraded. 

Symptoms: 

All of the below symptoms will occur - 

1. TIBCO Configuration Tool (TCT) gets the following error while upgrading BPM - 
  [echo] ================================================================= [echo] Task: Starting AMX BPM Application on BPM Node [echo] ================================================================= [echo] 28 Aug 2019 07:51:54 INFO - Executing action 'start' for 1 objects from data file '/opt/tibco/bpm_config_home/tibco/data/bpm/amx.bpm.app/deployment/integration_upgrade.xml' 28 Aug 2019 07:51:54 INFO - Starting Applications... . . 28 Aug 2019 08:08:52 ERROR - Application Start failed 28 Aug 2019 08:08:52 ERROR - TIBCO-AMX-CLI-000343: Start component 'apps' on node 'BPMNode' failed : java.lang.IllegalArgumentException: Exception during web application initialization. Deployment of web application failed 28 Aug 2019 08:08:52 ERROR - java.lang.IllegalArgumentException: Exception during web application initialization. Deployment of web application failed com.tibco.amf.runtime.implementationtype.webapp.WebAppImplementationAdapter.initImplementation(WebAppImplementationAdapter.java:242) . . caused by: javax.resource.ResourceException: TIBCO-AMX-HPA-014303: Failed to add context . . caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'roleRestService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.tibco.cap.roles.services.impl.RoleServiceImpl com.tibco.cap.roles.rest.RoleRestService.roleService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'repositoryComponent' defined in class path resource [app-repo-beans.xml]: Invocation of init method failed; nested exception is javax.jcr.RepositoryException: Cannot connect to the jcr/db..
2. BPM Node logs will have the following exception - 

28 Aug 2019 07:59:50,905 [ComponentFrameworkDelegate] [ERROR] com.tibco.repo.api.util.RepoContext - getCurrentSession() RepositoryException
javax.jcr.RepositoryException: Invalid repository configuration: {}
at org.apache.jackrabbit.core.TransientRepository$3.getRepository(TransientRepository.java:257)
at org.apache.jackrabbit.core.TransientRepository.startRepository(TransientRepository.java:280)
.
.
Caused by: org.apache.jackrabbit.core.config.ConfigurationException: Could not load JDBC driver class oracle.jdbc.driver.OracleDriver
at org.apache.jackrabbit.core.config.DataSourceConfig$DataSourceDefinition.isJndiConfig(DataSourceConfig.java:164)
at org.apache.jackrabbit.core.config.DataSourceConfig$DataSourceDefinition.verify(DataSourceConfig.java:146)
.
.
Caused by: java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver
at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:513)

3. TCT logs also indicate the newer version of repository.xml couldn't be extracted - 
 

-ext-oracle-repo-xml:
   [rename] DEPRECATED - The rename task is deprecated.  Use move instead.
Cannot rename nonexistent file /opt/tibco/bpm_config_home/tibco/data/bpm/amx.bpm.app/appdev/repository.xml_ORA