Well, this is embarrassing... AMD Radeon R7, AMD Radeon R9 360 (AKA Non-dedicated GPU), 1.67 TB of free space, 16GB DDR3 memory. I don't have an amazing computer, let's just say... But what can I do to use my hardware as efficiently as possible? I have already tried lowering resolution for preview, and that doesn't work, it just makes it harder to see what I'm doing. Same deal with lowering the FPS and clearing cache files, no effect. I downloaded VP yesterday, so I am using the latest version (and just in case, I reinstalled it). I'd much appreciate further help. P.S: The file is not very small.
EDIT: I just tested it, and now it only does it every once in a while, and it does say Building Preview now. Hooray.