This is a Windows folder/file access issue. Run your modeler as Administrator and it will most likely work. The easiest way to fix this is by checking out the project in a clean folder. Or you could try to set your user access correctly on your project folder and files in it but it's not a very straightforward interface in Windows.
The database in question here is actually not your application database but the project (mpr) file which is also a database (sqlite).