I just noticed this issue, not sure if it's due to a recent update. But when I have Mercury Transmit enabled to preview my comps on my second 1920x1080 monitor, AE tends to crash -- either on the creation of the new comp, or when switching between comps. Doesn't matter if the comps are the same frame rate/resolution or not. I have to force quit the app (opt-cmd-esc) to close AE when this happens.
If I disable Mercury Transmit and eliminate the second monitor video preview, the problem doesn't occur. This is a workable "fix," but I miss seeing my previews without markings on my larger second monitor.
Anyone else experiencing this? I don't recall ever seeing this problem before I noticed it today. When was the most recent update for AE?
Sorry for the multiple posts on this topic. When I tried posting this in the morning, the forum/server kept giving me a "too much traffic" error. I didn't realize each attempt actually posted my question.
Anyhow, I reverted back to AE 2020 v17.7 Build 45 and the problem went away. I can now create and change comps all while using my second external montior as a preview without issues.
So, something's up with Mercury Transmit on AE 2021 V18 Build 39 on macOS -- at least on my configuration.
I have this exact same issue. In my case I am using a 2 monitor setup on a Macbook Pro with the preview to the second monitor. It is a v18 issue from what I can tell as v17 has no such problem. Interestingly, I'm able to do a second monitor preview in the current version of Premier Pro just fine.
My system: MacBook Pro (16-inch, 2019) / 2.4 GHz 8-Core Intel Core i9 / 64 GB RAM / AMD Radeon Pro 5600M 8 GB