Microsoft Teams Calendar - maximum number of events for meetings

Your screenshot shows Save failing with “You've reached the maximum number of events,” but it doesn't identify the limit or its scope. I wouldn't delete meetings based on that wording alone. For a work or school account, compare creating one simple, non-recurring appointment in Outlook on the web with creating a meeting in Teams on the web, using the same account and calendar. Teams calendar integrates with Exchange, so that comparison helps distinguish a Teams-only problem from a broader calendar issue. Before retrying, check whether the previous attempt actually created an entry to avoid duplicate invitations. If only desktop Teams fails, record its version and update it. If web clients also fail, ask your administrator to review Teams and Exchange service health and open a support case with the exact error, UTC time and reproduction results. I can't establish a numeric cap from this screenshot.