I got this error message and had to reboot...

Goto Menu, Chart and Data Catalog...click on the top line of the chart list at the bottom of the screen and look for the file "SDUS01MAP3D04.dbt". Look at the status of that chart. If it says corrupted, try right clicking on that file and see if there's an option to "Repair". If so, choose that. If it says "OK" for the status, then there's nothing further to do.