I have not personally seen this error before, but as a first step I would check what calendar your schedule is trying to access. From the Ribbon, select Project > Project Information and check the calendar. Then check that this calendar exists. From the Ribbon, select Project > Change WorkingTime and check the For calendar setting.
From here you can either fix the calendar in the Change Working Time window or create a New Calendar. If none of this works, I would most probably reset my Global.MPT file back to the factory defaults. This will get rid of any customizations or corruption that you may have. To clear the Global.MPT file:
1)Close Microsoft Project
2)Make a backup copy of Global.MPT in your C:Users[your login name]AppDataRoamingMicrosoftMS Project141033 folder.
3)Once you have made a backup of the file, DELETE the Global.MPT file.
4)Open Microsoft Project.
5)Close Microsoft Project. (no need to save or do anything else). A new Global.MPT file has been created, all with default settings!
