- Open Calendar in the Vault and confirm that the expected events exist there.
- Try the CalDAV discovery address
lightdrive.one. If discovery fails or the app requires a full URL, usehttps://vault.lightdrive.one/remote.php/dav/. - Use the full LightDrive email address, preserving ID case, and a client password that includes Calendars access. A mail-only or contacts-only password cannot connect to Calendar.
- Confirm that the desired calendars are selected and enabled for synchronization.
- Check the device time, network access, background permissions, and battery restrictions.
If only one calendar is missing, re-enable that calendar rather than removing the whole account. Changing the main Vault password does not change a separately created client password. If you revoke or replace a client password, update the saved credential in your calendar client. Do not bypass an HTTPS certificate warning.
A shared calendar is missing or cannot be edited
Accept the invitation in Calendar → Sharing & invitations, refresh the calendar list, and select the calendar for sync. Check its sidebar checkbox if it is only hidden. Review the accepted permission: View only intentionally prevents editing, while Can edit events permits event creation, changes, and deletion but not calendar or sharing management. If the owner revoked access, changed the offer, or you left, a fresh invitation and acceptance are needed; replacing your client password will not restore sharing access.
Use a harmless test event in your own calendar to check two-way synchronization. Never disable certificate verification or ask someone to send you their account password.