For those of you who have been getting the Unable to Map File error, we've increased the error reporting so you should be able to see more information about the problem when it occurs.
For anyone able to reproduce the crash, please do so and Ctrl-C the error window and paste the information from the error here! This will hopefully help us find the root of the problem.
If you're getting the Unable to Map File error, and no report, you should also let us know!