Hi @Kántor Krisztina
Welcome to our forum!
What is your account? Outlook.com or Gmail.com or something else?
Does the issue occur recently on Outlook Desktop Client? Do you have any specific operation before the issue occurred?
In addiiton, here are some steps you may want to take:
- Check Account Type: Ensure your account is a Microsoft domain account (e.g., @outlook.com, @hotmail.com). If not, add one to Outlook and set it as the primary account.
- Update Outlook: Make sure you're using the latest version of Outlook. Sometimes updates fix missing features.
- Uninstall and Reinstall: Sometimes, it will also solve some unexpected problems.
Calendar > add calendar > add directory > missing
Based on my research, Add From Directory is a feature that Microsoft 365 accounts with licenses have, you may add a M365 account with license to see if there are any differences. (The picture above is without a license, and the picture below is licensed).
Hope it helps!
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