DRAFT KB-XXXX "An error occurred while retrieving the report" in Task per Process Model report

Symptoms

When looking at the Task per Process Model report, the following error appears:

The application server log throws the following error:

2016-12-15 19:20:53,204 [ajp-/0.0.0.0:8009-4] ERROR com.appiancorp.process.analytics2.service.ProcessAnalyticsServiceFacade - com.appiancorp.kougar.driver.exceptions.Signal: index
2016-12-15 19:20:53,204 [ajp-/0.0.0.0:8009-4] ERROR com.appiancorp.process.analytics2.display.ProcessAnalyticsReportData - com.appiancorp.kougar.driver.exceptions.Signal: index
java.lang.RuntimeException: com.appiancorp.kougar.driver.exceptions.Signal: index

Cause

One of the cause of this issue can be that:

1. A constant has been created with the same name as a task metrics.
2. The Execution and Analytics engines are out of synchronization and need to be synchronized again.

Action

To fix this issue, first verify if a constant exist with the same name as a task metrics. To do so, follow these steps:

1. Navigate to the Rules tab
2. Using the search box, check if a constant with any of these names exist: 

• task_avg_completion
• Completion
• task_completion_time
• is_process_ontime
• is_process_overdue
• is_task_favorite
• is_task_ontime
• is_task_overdue
• Lag
• NetCompletion
• NetLag
• NetWork
• process_completion_time
• process_deadline
• process_ee_id
• pm_avg_completion
• pm_avg_lag
• pm_avg_work
• process_start_time
• task_assignee_owner
• task_assignment_time
• task_attributed_to
• task_avg_lag
• task_avg_work
• task_deadline
• task_ee_id
• task_status
• total_completion_time
• total_lag_time
• total_work_time
• Work

If a constant with a similar name exists, remove it from the system. 

After making sure that no constants exist with a same name as one in the list above, reset the analytics engines. Please refer to KB-1157 How to reset the analytics engines for on-premise installations of Appian for more details.

Affected Versions

This article applies to all versions of Appian.