If you have the project finish date locked by a custom process, you can extend the project finish date with XOG, MSP or OWB changes, but the finish date cannot be brought be in to an earlier date.
There are neither assignments nor team members to lock in the dates with a curve.
This worked without issue in 12.1.1 and appears to have changed behaviors with 12.1.3.X.
Steps to Reproduce:
Expected Result: Project Finish Date to display as 6/24/2013 and schedlog to reflect 6/24/2013 as project and task finish dates
Actual Result: Project Finish Date is still 6/26/2013 in spite of schedlog clearly showing we sent 6/24/2013 through for the task and project finish date
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Release: ESPCLA99000-13.2-Clarity-Extended Support Plus