Greenscreen render immediately drops to 0

Hey folks. On both my M1 macbook pro 16gigs model and my Windows 10 machine with 3800xt ryze, 64gigs of ram and 3070 card, I have a greenscreen project that immediately drops to 0 and crashes Davinci when I try to render. It's 4k timeline for a 1080p render, but changing codecs, resolutions or even complete hardware doesn't fix it. Now here's the kicker: playback is FINE. Does anyone have any solutions? I'm getting kinda desperate here.

I FINALLY found what it is - it's the face refinement effect. Anyone know what causes this?

A 4K timeline for a 1080p render only makes your edit playback slower. If you intend to deliver 1080p and your source material is 4k, set your timeline to 1080p. When you render, Resolve always uses the full source resolution.

Of course, this doesn't fix your render-time crash, but it'll make editing more responsive, especially with heavy effects.

If there's a particular effect that's causing crashes, you can fiddle with Resolve's GPU settings in the preferences->memory and GPU. The options it presents to you depend on your system. If that doesn't work, and you've installed the latest driver for your GPU, you might consider downgrading. If you don't have the latest driver, try upgrading. Another tactic is to limit Resolve's maximum render speed on the deliver page, which can help in certain situations, like components overheating.