Agile Board configuration page load timeouts due to long JQL execution

Summary

Agile Board configuration page fails to load due to longer JQL query execution (a query takes longer than 60s default JSON timeout)

Steps To Reproduce

Configure board with long and complex JQL, with an execution longer than the 60s.

Expected Results

• The board should continue loading anyway
  or
• A meaningful warning/error message should be displayed with related reason:
  • default timeout information
  • long JQL execution
  • other root cause

Actual Results

The board does not load, no effective error message provided to the user.

Workaround

Some recommendations and workaround are available in the KB:

• https://confluence.atlassian.com/jirakb/how-to-change-the-default-ajax-timeout-in-jira-824345485.html