Changing a finish date for a task constrained by a date
The task whose finish date you're changing is constrained so that its finish is tied to a specific date. At some earlier time, this task was given a finish constraint. Changing the finish date will remove the constraint. If you want to keep the original finish constraint, cancel the change with the Planning Wizard.
Using the Planning Wizard, you can:
Leave the finish date unchanged and keep the constraint.
Microsoft Project will not change the task's finish date. The task's start or finish will remain tied to the constraint date.
Change the finish date and remove the constraint.
Project will change the task to finish on the date you have specified by placing a Finish No Earlier Than constraint on the task and will remove the old constraint.
If you don't want the Planning Wizard to display this information again, select the Don't tell me about this again check box.