"Task history will be deleted" message after editing Billable flag

SYMPTOMS
A user is having an issue updating the chargeable flag for a Project. After she opens any of the tasks, edit, update or save, she gets popup message of “Task history will be deleted. Do you want to continue?” She wasn’t getting this message before. She tried a different project and didn’t get it either. It seems to be happening on all the projects in which she changes the project from Non-Chargeable to Chargeable, save and then go in and edit the task to update.

REASON
If the billing status is changed in the task editing screen an Effective Date check box displays.

The Billable task check box may not be available to change if the Allow the project manager to override the [Billable] status check box is not selected on the Engagement dialog box. If the change affects only some of the time records, select the check box and enter the effective date. The change only affects time records from the effective date onwards. This will be kept as a historical record and any new invoices created will respect that effective date. If the change is to affect all your time records, do not check the Effective date check box.

RESOLUTION

If an effective date was previously entered for billing status and you do not select an effective date now, you will receive a warning message that all history will be cleared. If the new billing status is to be effective for all your time records booked, do not enter an effective date. This clears all history (by not selecting an effective date). As a result, all time that has not been invoiced will respect the current billing status.