When I create a schedule, save and close it, the next time I open it the activities have rearranged their location on the schedule. Activities that were numerically placed 1,2,3,4,5,6 are now all mixed up in a different order. Predecessors are now physically located underneath the activity they were previously above. Predecessor/successor links are correct, dates are correct but the order is jumbled up. I can relocate them all but after saving, closing, and reopening the schedule the order will all be mixed up again but in a different mix than before.
Do the tasks have the same task ID numbers, but are simply displaying in a different order?
I don’t know that this will fix the issue, but check the view that is initially displayed when the schedule is opened. For example, does it have a Filter or some Grouping parameter specified? Is that view an out-of-the-box view that you can’t modify, meaning changes you make to it will not be saved?
Just some thoughts
Cheryl, Since you mentioned the order is mixed up or sorted after reopening the file, I doubt if there is any VBA macro code that sorts the tasks when the file is opened. Please check View > Macros > Visual Basic and double click the project name. If the editor displays any code to sort the tasks on Project Open event, please delete it.