So lately I've noticed that if I quit BOINC and restart it that Asteriods@home, Einstein@home, and Milkyway@home wu's will say that there's been a computation error. I'm running MacOS 11.2.3 with BOINC 7.16.14.

I'm not aware of any issues with stopping those project's tasks and restarting them. The default checkpoint in the Manager of 60 seconds should create a checkpoint to restart from.

Some projects either don't create ANY checkpoints and some projects don't like stopping a task midpoint and do error out a lot. GPUGrid and Minecraft come to mind with my experiences.

I'm thinking that permissions on the BOINC folders might be an issue where the restart of the client after stopping for some reason does not have read/write access again to the original task checkpoint and that produces the error.