Server responded with an error
There are lots of posts out there for this issue on the Mac calendar. I've reset both rams and started in safe mode and still have the problem for my google calendars. It's new. What to do?
MacBook Pro 13″, macOS 10.14
Apple changed something, and now we're all having these problems starting around 7pm EST every day, which re-sets some time in the early morning (so it works fine during the day). Here's some coverage of the issue: https://forums.macrumors.com/threads/ical-calendaragent-error-mismatch-token.2285958/