To allow Users to populate changes made to the a Standard tasks to it's recurring tasks, without having to leave the "Edit Standard Task" screen, the Recurrences "It looks like you have unsaved changes..." message was introduced.
The feature however fails to save changes made to Tasks' checklist questions. When you click on "Save" to save the changes the following error is displayed in developers console:
"Uncaught ReferenceErrors: button is not defined"
This issue was fix in Fewzion v14.0, to upgrade to the current version of Fewzion please contact Fewzion support.