We are currently running MS Project 2013 configured to only allow task updates via timesheets. We see the same error and it’s a bug in project. We’ve found that Project will on occassion, plug zeroes (0) into the future actuals fields for some resources on some tasks. Meaning, if you look at a Task Usage Time Phased view of the data, you will find resources that have values of 0 (not null/blank) in their actuals fields for future weeks. We’ve also seen this occurring in the past where project will add zeroes to the actuals 1, 4, 8, etc. weeks prior to the tasks actual start date. We’ve reported this bug to MS and it was supposed to have been fixed in a recent CU (we’re up to July) but it wasn’t.
What the error is telling you is that the scheduling/leveling engine is trying to adjust the task, but moving the task on the timeline would mean changing what it thinks are actual hours entered by timesheets.
How do we get around it?
In some cases we can’t. We will occasionally schedule what we call blackout periods where we block all PM access to the tool, turn off the switch to only allow actuals entry via timesheets, and then we manually fix project schedules by removing the zeros manually. After all known schedule problems are fixed, we reset the actuals entry by timesheets only switch and then open access to the tool to all PMs.
Some other things we’ve found that occassionally work.
1) In a Task usage view for the task having the issue, identify the resource(s) containing the erroneous zeros into the future and play around with adjusting the resources remaining work. Set the value to 0, set it back to what it should be, etc.
2) As dumb as this sounds, switch the task from Auto Schedule mode to Manual schedule mode. We’ve seen scenarios where every switch from Auto to Manual removes a week of zeroes from the future. So you may need to do this many times. We can see no reason this should work, but it sometimes does.
3) In timesheets, open up the Actual Finish date for entry. Have the resources with zero future actuals enter in an actual finish date of the desired date. Then, once they are processed, the PM should go back and adjust the remaining work as necessary.
We’ve been dealing with this bug/issue since we installed Project 2013 in May and we can’t determine what specifically is causeing these sitiuations to occur.