I have a test 18 minute 4K UHD edit on the timeline of Vegas Pro 14 latest build. Two video tracks; video and titles; one audio track. Total 22 GB. Attempts to render to apparently compatible ProRes CoDecs result in an unplayable file. (VLC). Render to the Internet 4K works perfectly. I have QT 7. Asus i7-4770, 16 gb, nvidia 4gb. win 10