Previously, I wrote about Time Machine “error 45”, an obscure bug in macOS Catalina. I still have no idea what was causing backups to fail, nor what “error 45” means. However, I am happy to report that I think this issue has been fixed in Big Sur.
I was ready celebrate that my upgrade to macOS Vista Catalina was successful. Zero issues, zero data loss, only the expected barrage of securitytheater dialogs. And then Time Machine backups started to fail.