This just started happening today. Quicken version R59.18. No error message. Getting a wait cursor and no further response from Quicken
Opening the calendar does not crash or lock up Quicken for me, so it's probably not a systemic Quicken issue. I would suspect data file corruption. As a first troubleshooting step, have you validated and super validated your data file(s)? Alternately, restore a known-good data file backup.
RalphC, thanks! Validation fixed it.