I have an iPhone 16 Pro Max, the latest iOS 18.1.1, latest Vaultwarden on Start9 server 1.32.5 (released 1 week ago), and latest Bitwarden app on iOS 2024.11.0
Previous to upgrading my iPhone from a 15 to a 16, my Bitwarden app worked when directed to my self-hosted address. Now with the new phone, I set up everything the same but keep receiving the error “an error has occurred” after I enter the username. I also tried on my iPad to see if the error replicates and it does on there as well.
I couldn’t find anyone with a resolution that worked for me so far. I have tried uninstalling and reinstalling iOS app, downgrading and upgrading again my server Vaultwarden on start9OS to no avail unfortunantley. I am able to use Bitwarden no problem on web and webplugins
Vaultwarden is not a Bitwarden product. Unless you can reproduce the issue while using Bitwarden’s cloud vault or Bitwarden’s self-hosted vault, you are probably better off asking for assistance in the Vaultwarden reddit (https://www.reddit.com/r/vaultwarden/new/)
One important thing might be the identity certificate, if Vaultwarden also uses one. On iOS, this must be trusted on the device, which a self-signed one (as suggested for self-hosting) will not work.
As already noted by @DenBesten, Vaultwarden is not supported by Bitwarden, as it is an independent product. From time to time, there will be
compatibility issues between the official Bitwarden client apps and the Vaultwarden server, when Bitwarden implements changes to its own server software (which have not yet been mimicked by the Vaultwarden devs).
It is generally not possible for members of the Bitwarden community (users or developers) to help with such issues, but Vaultwarden has its own community spaces where you can seek support:
Vaultwarden developers have clarified their position on providing support for Bitwarden client incompatibility issues in the notice at the top of the Vaultwarden project’s GitHub README: