Error: "Could not find suitable statistics field with ID 'customfield_<your_id_number>'."
A custom field used by the Agile Plugin was removed. Now, whenever you click on the plan section of an agile board, you see an error message stating: Error: "Could not find suitable statistics field with ID 'customfield_<id_number>'."
The custom field was used by the Agile Plugin. It is not recommended that fields be removed unless it is planned and tested.
From the Rapid Board screen, the solution is to click Tools > Configure > Estimation Tab.
Select the appropriate option from the Estimation Statistic drop down menu.