TR0815
The interval between the year start-days for alternate drill-down paths drill_down_name1 and drill_down_name2 in dimension dimension_name must be equal to one or more whole units of time as represented by the convergence level.
You have created an alternate drill-down structure in the time dimension and specified incompatible dates for the Year begin days in each drill-down path.
Procedure
Correct the settings on the Time tab
of the appropriate property sheet, so the dates in each drill-down
path align correctly.