macOS Calendar App and Nextcloud CalDAV "Unable to verify account name or password"

[benbusch]

Nextcloud version (eg, 20.0.5): 28.0.3
Operating system and version (eg, Ubuntu 20.04): macOS 14.4.1
Apache or nginx version (eg, Apache 2.4.25): Linux 4.18.0-513.9.1.lve.el8.x86_64 x86_64
PHP version (eg, 7.4): 8.1.27

The issue you are facing:
I cannot connect my CalDAV to any Apple device on any network, and I have exhausted all documented solutions (e.g. 1, 2). In every instance, Apple’s Calendar app returns the error “Unable to verify account name or password”. I have confirmed with my host that SSL/TLS certificates follow Apple’s requrements. From my host: “Lets Encrypt issues 2048bit certificates and TLS is also 1.2 or higher.” Edit: I am able to connect to CalDAV with Thunderbird on Ubuntu 22.04, so I know it is possible at least from Linux systems.

Is this the first time you’ve seen this error? (Y/N): N

Steps to replicate it:

1. Open Apple’s Calendar app
2. Select: Calendar > Add Account
3. Select Other CalDAV Account
4. Change Account Type to Advanced
5. For User Name, insert email associated with the Nextcloud account, for Password the password associated with the Nextcloud account, for Server Address the domain of the Nextcloud instance until and including the TLD, for Server Path everything after the TLD including the first slash copied from the Nextcloud Calendar settings button “Copy iOS/macOS CalDAV address”, for Port 443, and Use SSL is checked.

[benbusch]

Lösung:

1. Open Apple’s Calendar app
2. Select: Calendar > Add Account
3. Select Other CalDAV Account
4. Change Account Type to Manual
5. For User Name, insert email associated with the Nextcloud account, for Password the password associated with the Nextcloud account, for Server Address the domain of the Nextcloud instance until and including the TLD, followed by the port, e.g. company.provider.com:443