Trouble with iOS Devices CalDav/CardDav on one newly installed AIO-Instance

[neocult-de]

Hi everyone,

I have several Nextcloud-AIO instances, behind npm and/or with dedicated ip. On my latest instance I can´t get iOS to connect the Nextcloud profiles (CardDav+CalDav) to work anymore. Error: The operation couldn´t be completed: DAAccountValidationDomain error 102

On the other instances it works. All are on latest stable. I put the current instance on a dedicated IP and even configured the PTR / Reverse Entry for the Domain. I have LetsEncrypt certificates auto-generated as usual, CalDav/CardDav URLs work normally if called in a Browser, Thunderbird, Android, but just iOS doesn´t seem to work, and only on this one instance.

Anyone experienced that with Nextcloud-AIO? How would I debug this further? Checking the forwarding of URLs, use the iOS-specific Addresses / use the Profile under Mobile & Desktop both don´t work with the given error message.

As it is set by default overwriteprotocol https is set in the config, which sometimes can be an issue. And it is not 2FA, i tried directly with more than one user account and direct password and app password either way.

Looking forward to any hint. Thank you very much.

[neocult-de]

I was able to narrow down the issue to getting that issue only if it is the root-Domain. All other instances on a subdomain have no issue and if I change the current domain to a subdomain of it, it starts to work as intended under iOS.

Still only iOS seems to check something more about a domain than just using the settings provided by the profile as any other app. But then it might not be Nextcloud-AIO related, but something about service discovery and other systems configured within the domain.

[neocult-de]

I finally figured it out over the weekend, after waiting for the DNS Caching to be a non-issue. If you are with a hoster, where Domains might already have SRV and TXT-Records for caldav and carddav services and they don´t match your nextcloud instance, an iOS Device will refuse working and throw error "The operation couldn´t be completed: DAAccountValidationDomain error 102" when trying to add a Nextcloud profile.

If you want to set proper discovery entries in DNS you have to set SRV AND TXT entries for the domains:
_caldav._tcp.yourdomain.com.
_caldavs._tcp.yourdomain.com.
_carddav._tcp.yourdomain.com.
_carddavs._tcp.yourdomain.com.

Whereby the SRV records have
Priority: 0, Weight: 0, Port 443, Target: yourdomain.com
and the TXT records have
path=/remote.php/dav/

For future reference I wanted to have that out there, as using search engines it is hard to find anything related to that error code and other platforms don´t block using nextcloud with wrong or no dns entries at all and there is no direct link to this if searching in general for iOS and Nextcloud Sync issues.

[artwaw]

Thank you for that, I tried to import mobile profile from the next cloud to apple device and got hit by that error!

[papalamg]

Hallo, i have also an error DAAccountValidationDomain error 100.
In my local network I have a lets encrypt wildcard certificate which is shown as valid for my next.damoain.com when I log in via web interface.
I have a local DNS (adguard) where I have a Local DNS Records [A/AAAA] from next.mydomain.com on the ip address of my server.
How to set the SRV and TXT entries? Must this be done in adguard? How?