Over and over again. I excluded the directory Rosetta and BOINC resided in for virus scanning

That will exclude them from the virus scanning, but not necessarily from the real-time protection. So when they start up (or try to access the Internet), the AV may block them. And using FOUR is asking for trouble. They are probably tripping all over each other as they try to inspect the same file or operation.

I use at most one virus scanner, and sometimes not even that. I have had to re-install operating systems more than once because of disk corruption due to AVs, but never due to viruses.

(And if you don't want malware, don't install it. It usually does not install itself.)