Oracle BPM 12C - Cannot open web form in composer

When I was trying to open Web Forms tab in BPM composer , i got the the following error all the time 

Error 500
Oops, an error has occurred. If the problem persists please contact your administrator.

Caused by: java.lang.NullPointerException: entryId is null
at com.frevvo.forms.client.FormsService.getEntryURL(FormsService.java:598)
at oracle.bpm.webform.service.WebFormsService.getApplicationsForProject(WebFormsService.java:591)
at oracle.bpm.webform.service.WebFormsService.deleteAllApplications(WebFormsService.java:481)
at oracle.bpm.webform.service.WebFormsService.getProjectForms(WebFormsService.java:231)
at oracle.bpm.composer.bpm.editor.webform.manager.WebFormStateManager.initFreevoForms(WebFormStateManager.java:236)
at oracle.bpm.composer.bpm.editor.webform.manager.WebFormStateManager.getFrevvoForms(WebFormStateManager.java:607)
...


Solution:


This issue was caused due to a missing JVM parameter: -Djava.awt.headless=true

The server needs to be started with java.awt.headless=true because it is started from a non-graphic console. This is needed for all server apps and is not specific to WebForms.

Steps:

1. Edit the "startManagerWeblogic.sh" script
2. Add the "java.awt.headless=true" to the JAVA_OPTIONS JVM environment variable
3. Restart the Managed Server.