When trying to open a schedule in MS Project, the schedule will not open and an error message indicates that the schedule cannot be opened. This same project schedule will open in the PPM gantt. However, when opening specific task properties, several tasks present a generic system error message.
The app-ca logs contain the following line for the corresponding error message:
Error message: [CA Clarity][Oracle JDBC Driver][Oracle]ORA-01427: single-row subquery returns more than one row
The task WBS structure gets corrupted. This is due to a known defect, DE41568.
DE41568 has been fixed on PPM 15.5.
Indent/outdent the affected tasks in the PPM gantt until the desired task structure is achieved.