After the new update, I can't pre-render anymore. I don't know what happened. Can some help me?
What are you attempting to pre-render.
Is it a composite shot and a media file.
I thought that.
My guess is that with the addition of proxies in the new version, you are expected to created a proxy for media files which have playback performance problems on your machine. This may be why media files are disabled for pre-renders.
Pre-renders are actually very wasteful when used on media files. Pre-renders were designed to help complex composite shots perform smoothly when nested into another composite shot or editor timeline. It is easy to create effects composites that will never play smoothly regardless of your hardware. Hence the pre-render feature.
For media files that do not decode smoothly. That is what proxies are all about. Hitfilm now has proxies. Use a proxy if you need to.