"Exception message: Connection failure" when setting up Android App [SOLVED]

Hello friends!

Initially I was posting to figure out why I couldn’t get Vaultwarden to work with the Bitwarden Android App. In so doing, I followed the steps outlined in this forever-relevant masterpiece: How To Ask Questions The Smart Way .

In writing out the problem per the article, one of the things indicated is to do a search of the forums and see if there was anyone else having a tangentially-relevant problem, and indicate what makes my iteration of the issue different from theirs.

That brought me to a post that said “check your Nginx logs”, which I did…and they didn’t indicate any attempt to talk to the server, but they did indicate that there was an issue with my cert. Unlike most users who use Let’s Encrypt or ZeroSSL’s API, I’m using commercial certs.

What solved the issue for me is that Vaultwarden demands a Full Chain SSL Certificate, which I did not implement. Firefox and Opera are fine with just the regular cert, but the app wants a full-chain cert. Once added to my reverse proxy, the app started working normally.

To make one of these, copy/paste the CA bundle supplied with your cert to the BOTTOM of the issued certificate for your domain. Alternatively, copy/paste your issued certificate into the box on this website: Certificate Chain Composer - Generate Intermediate Certificates | KeyCDN Tools , and it’ll generate a full-chain certificate that can then be added to the reverse proxy. Restart Nginx, and everything will work perfectly!

I hope this helps someone else who runs into a similar issue.