green check mark with yellow exclamation point

I did a couple of outputs a few days ago using proxy media. Though I've since reconnected to the full resolution media, I keep getting the green check mark with the exclamation point next to all my outputs in Media Encoder. 

When I click on the check mark, I get a long error log about my outputs from a few days ago plus thousands of lines of "A low-level exception occurred in: Mercury Playback Engine GPU Acceleration (Metal) (AcceleratedRenderer:2)". I have many unrendered resize effects in my timelines plus a Lumetri adjustment layer; but I've done outputs in the past with the same number of unrendered effects and didn't get the yellow exclamation point. Again, the log seems to be pointing to outputs I did using proxies from several days ago. Any ideas what's going on?