We followed all the installation steps for upgrade from BC 6.X to BC 7.X but on the Initialize Database step, we are getting the below error :
<<<
2020 Mar 12 11:11:20:490 GMT -0500 :  com.tibco.ax.fw.cfg.common.BCInstallationException: java.security.InvalidKeyException: Illegal key size
    at com.tibco.ax.fw.cfg.factory.InstallBC.init(InstallBC.java:174)
    at com.tibco.ax.gui.bcwebadmin.consoles.config.ConfigJdbcPanel.createInstallation(ConfigJdbcPanel.java:962)
    at com.tibco.ax.gui.bcwebadmin.consoles.config.ConfigJdbcPanel$10.actionPerformed(ConfigJdbcPanel.java:811)
    at com.tibco.wfc.AbstractComponent.notifyListeners(AbstractComponent.java:143)
    at com.tibco.wfc.AbstractComponent.fireActionPerformed(AbstractComponent.java:133)
    at com.tibco.wfc.AbstractComponent.processCommand(AbstractComponent.java:157)
    at com.tibco.wfc.AbstractFrame.processCommand(AbstractFrame.java:115)
    at com.tibco.wfc.FrameManager.a(FrameManager.java:259)
    at com.tibco.wfc.FrameManager.service(FrameManager.java:147)
    at com.tibco.administrator.AdministratorServlet.service(AdministratorServlet.java:958)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at com.tibco.administrator.AdministratorServletFilter.doFilter(AdministratorServletFilter.java:56)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:110)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:494)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:1025)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:445)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1137)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:319)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:748)
>>>
We are using Oracle database.

All environments using Oracle databases

To use TIBCO BusinessConnect security features, you must download and install the following two JavaTM Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy files:
Java 1.8.0 Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files 8.0.
This is required for JRE 1.8.0.

To download and install the policy files, perform the following steps:
1.  Stop all engines and the Administrator/Hawk Agent
2. Download the required files from the following websites:
— Windows, Sun Solaris, Linux
     http://www.oracle.com/technetwork/java/javase/downloads/index.html
— IBM AIX
     https://www14.software.ibm.com/webapp/iwm/web/preLogin.do?source=jcesdk
3. After downloading the jce_policy-8.zip file, unzip it and place the files US_export_policy.jar and local_policy.jar into the following directory:
TIBCO_HOME\tibcojre64\version\lib\security
4. Restart Administrator/Hawk Agent and the BC engines.
 

Get an invalidKeyException when trying to initialize the BusinessConnect Database

Illegal key size, JCE, security