KB-1569 "An error occurred while retrieving the report" in Task per Process Model report


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


Potential causes of this issue are:

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


To fix this issue, first verify if a constant exists with the same name as a task metric. 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 self-managed installations of Appian for more details.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: April 2018