[Ivan Engler]

have the same problem here since i upgraed to 12.1.

MAC PRO 2011 with 10.8.5 rendering MP all 12 cores (24 hyperthreaded), 64 GB RAM, 2GB to each core.

the “red flash frames” appear in my renders when using prores 422HQ clips as footage items in my comps – but also when rendering without prores clips in comps when i apply lens blur as effect (???why???)

in other situations, the flas frames do not seem to appear

when i use png sequences as footage items, the problem seems NOT TO HAPPEN

the “red flashframes” appear in random locations – even if i render the same clip 5 times, the red flash frames appear at different, completely random positions.

it also happens after a fresh reboot and no other apps running.

–> seems really random
i suspect a specific 12.1 bug and hope for a soon update
12.0 always worked like a charm – this bug appeared only since last week when i upgraded