This issue is fixed in CA PPM 15.4.
Workaround: Rebaseline the project in PPM, then the project should open.
To rebaseline the project:
1. In PPM, click on the link to the Project
2. From the Project Properties drop down, select 'Baseline'
3. Click 'New' and enter the required information
4. Click 'Save' or 'Save and Return'
- Note: Check in Administration->Project Management->Settings, to make sure 'Only Export Current Baselines When Opening Investments in a Scheduler' is checked to prevent the problematic baseline from being exported. IMPORTANT: Be sure to only make changes to this setting when all projects are checked in from MSP and OWB. Changing this setting if a project is checked out can result in the loss of baseline data. Lost baseline data is not recoverable.