Symptoms

This only applies if you've managed to modify an agile simplified workflow for a project by deleting it than manually recreating one and associating it to the Project that still had issues in the project. As a result, you can no longer access the Issue Navigator, as it produces a 500 error page. 

It will be noted several times during the removal of the simplified workflow that you should not do it, but if you get to this state,  leverage the workaround below to rectify this;

Example of a warning you will see while trying to modify the Simplified workflow (There are several similar warnings this along the way to reproduce this):

"Generated by JIRA Agile version 6.6.0-D20140904T040435. This workflow is managed internally by JIRA Agile. Do not manually modify this workflow."

Although you won't have access to the logs for your cloud instance, support can observe the following appears in the atlassian-jira.log whenever you go to Issue Navigator as the page will load with a 500 error:

2014-09-10 11:12:13.794451500 Sep 10, 2014 11:12:13 AM org.apache.catalina.core.ApplicationDispatcher invoke

2014-09-10 11:12:13.794453500 SEVERE: Servlet.service() for servlet action threw exception

2014-09-10 11:12:13.794453500 java.lang.NullPointerException

AND/OR:

An unknown exception occurred executing Validator com.atlassian.jira.workflow.SkippableValidator@130d55: root cause: java.lang.NullPointerException

Diagnosis

As an admin you can see the following process followed to get the instance into this state, and whenever you go to Issue navigator a 500 error will appear: 

09/Sep/14 9:59 AM    System Administrator    workflows       
Workflow deleted
Agile Simplified Workflow for Project CAW Show more


09/Sep/14 9:59 AM       System Administrator    workflows       
Workflow scheme deleted
Agile Simplified Workflow Scheme for Project CAW  Show more


09/Sep/14 9:59 AM       System Administrator    projects        
Project version created
Version 3.0     Show more


09/Sep/14 9:59 AM       System Administrator    projects        
Project version created
Version 2.0     Show more


09/Sep/14 9:59 AM       System Administrator    projects        
Project version released
Version 1.0     Show more


09/Sep/14 9:59 AM       System Administrator    projects        
Project version created
Version 1.0     Show more


09/Sep/14 9:59 AM       System Administrator    workflows       
Workflow scheme added to project
Sample Scrum Project    Show more


09/Sep/14 9:59 AM       System Administrator    projects        
Project created
Sample Scrum Project    Show more


09/Sep/14 9:59 AM       System Administrator    workflows       
Workflow scheme created
Agile Simplified Workflow Scheme for Project CAW  Show more


09/Sep/14 9:59 AM       System Administrator    workflows       
Workflow created
Agile Simplified Workflow for Project CAW Show more


08/Sep/14 5:00 PM       System Administrator    projects        
Project component updated
Other   Show more 

Additional Troubleshooting that can only Be Performed by the System Administrator (Atlassian Support Engineer account), Requires Trouble ticket for diagnosis (Here for referance):

SQL Query:

jira=> select workflowname from jiraworkflows where workflowname like 'Agile%';
                workflowname                
--------------------------------------------
 Agile Simplified Workflow for Project ABC
 Agile Simplified Workflow for Project UNOME
 Agile Simplified Workflow for Project 123
(3 rows)

Should Return All simplified workflows if the Project in question is missing 'CAW' from my example case.

Sysadmin can also Run the Integrity Checker and will Get Results like the following:

Check Workflow Integrity
PASSED: Check workflow entry states are correct

Check workflow current step entries
UNFIXABLE ERROR: The issue with key CAW-1 has a status of To Do which is not a valid status for the issues workflow. (JRA-8326)
Check workflow current step entries
UNFIXABLE ERROR: The issue with key CAW-2 has a status of InProgress which is not a valid status for the issues workflow. (JRA-8326)
Check workflow current step entries
UNFIXABLE ERROR: The issue with key CAW-3 has a status of Done which is not a valid status for the issues workflow. (JRA-8326)

Cause

There are reasons to delete the simplified workflow, but this should only be done if all the issues associated to to the project have been Moved to a new Project and you are no longer using this workflow.  The Status of the issues are stuck in the "To Do, In Progress, Done" (As noted above in the Sysadmin troubleshooting steps) state but those statuses no longer exist according to the DB because their project key association was deleted when the project was.

Workaround

The fix for this is to perform a bulk edit and change the Status on the issues, which the first step requires going to the issue navigator, but because of the bad state the issue navigator is not navigable.  So to bypass the issue navigator you can do the following:

1. GO TO:
   1. Projects > View All Projects
2. Select The effected project
3. Select 'issues' in the 'Summary' Payne
4. Select All Issues and this will get you to the point to perform a bulk edit

Perform a bulk edit and change the Statuses.

In terms of proceeding, raise a support request at: https://support.atlassian.com  and reference this knowledge base article in your support case to speed up the process as well as what you have done so far.

At that point, a support engineer will work with you to: 

• Bring Down JIRA and Manually rebuild the system cache
• Perform a full reindex of your cloud instance