'Invalid Duration' error when setting the Actual End Date on a milestone


When changing the 'Actual End Date' on a Milestone project task, an error message is displayed below the state field: "Invalid Duration".

This happens without submitting the form.


Changes on the "Actual End Date" field triggers a set of client scripts to change several fields including State.
These scripts rely on the form information (g_form object) and the Planned Duration fields is taken into account when validating the dates. Since Planned Duration is not present in the form, the system is unable to determine if the duration is set properly.


The Planned Duration field will need to be present on the form (even if not visible) so the client scripts and Ajax calls to project calculations work properly.
To fix the issue you can: