outlook calendar not allowing recurring appointments to be saved.

Take this for the cause and fix:

1. Corrupted Outlook Profile or Data File

• If your Outlook data file (.pst or .ost) is corrupted, it can prevent appointments from saving properly.
• Fix: Try repairing your Outlook data file using Microsoft’s built-in tool. 

2. Too Long or Complex Recurrence Pattern

• Outlook sometimes struggles with long or complex recurrence rules (e.g., daily for 6 months).
• Fix: Try simplifying the recurrence, break it into smaller chunks (e.g., weekly blocks) or use fewer exceptions.

3. Calendar Sync Issues

• If you're using shared calendars or syncing with mobile devices or third-party apps, conflicts can arise.
• Fix: Check if the issue persists in Outlook Web Access (OWA). If it works there, the desktop client may be the problem.

4. Outlook Running in Compatibility Mode or Add-ins Interfering

• Add-ins or compatibility mode can interfere with calendar functions.
• Fix: Run Outlook in Safe Mode (Outlook.exe /safe) and try saving the appointment. If it works, disable problematic add-ins.

5. Permissions on Shared Calendars

• If you're adding appointments to a shared calendar, permission settings might block changes.
• Fix: Double-check that you have full editing rights for the calendar in question.

6. Outlook Version or Updates

• Some versions of Outlook have bugs that affect recurring appointments.
• Fix: Make sure your Outlook is fully updated. If you're using Microsoft 365, check for known issues or try reinstalling the app.