We've noticed this behaviour for (I believe) a few months now: when we launch a new build of our game, two macOS anti-virus/AV-related processes – XprotectService and syspolicyd – seem to kick into high gear, using 100% CPU resources. Importantly, during this time the app doesn't seem to be open... we can see the new icon bouncing in the dock (since it's a new process there), but there is no actual output to player.log during this time. Eventually, XprotectService and syspolicyd finish their processing, and the game launches, and logging begins. In fact, during testing, it seems like the time spent waiting for those processes to finish is relative to the size of the build: a small test scene (~100MB) launches in a few seconds; the full game (on the order of ~10GB) can take several minutes before launching. Another interesting point is that this behaviour only seems to happen the first time running a new build – all subsequent launches get into the game in a matter of seconds, regardless of the size of the build. Further, we are seeing what we think is similar behaviour on Windows, where new builds seem to trigger an AV software response, and take a long time to launch. Again, this only occurs occasionally. I realise these processes are outside the scope of Unity support, but surely there have been even larger games (on the order of 100s of GB) which have not consistently triggered an AV response and a subsequent delay in launching. We've been on 2019.4 for a while now – is it possible that this introduced something that the OSs are flagging? Or are macOS Catalina and newer versions of Windows behaving differently, and are other Unity devs noticing/adapting to this new behaviour?