I'm trying to learn how to build/burn a dual layer DVD for the first time, but can't seem to figure it out. I set the Properties to the right settings, I think:

Properties > Disc Properties > Target media size(GB) 8.5

Mastering > DVD-ROM type > DVD-9 (8.5)

Is there something else I need to do? The error is just vague, says it doesn't know what went wrong. I'm on a PC, if that makes a difference.

Edit: When I click Optimize Disc it says the file is too big, but it's only 7.5GB, so it should fit on a dual layer DVD.