How to remove a certificate exception

Brand new to NextCloud so please be kind. On initial install of the Linux Desktop client on Ubuntu 18.04 I manually accepted an SSL certificate which NextCloud said it couldnt verify. I have subsequently used OCC to install a certificate. But when I click the green lock in the Account cponnection the client continues to indicate “This certificate has been manually accepted.” How do I delete the certificate exception and convince the client to authenticate again? Full disclosure: I used openssl to create my own (self-signed) CA certificate and installed that cert into my system’s trusted certificate store. I then used openssl to use that CA to sign the end-user certificate I installed for NextCloud to use. Thanks for any help.

After a bit of searching and trial-and-error, I answered this myself:

  1. From the Connection tab of the client, click Account > Remove, then exit the client
  2. Use a file manager to browse to /home/(user)/.config/nextcloud and delete all the files you find there – specifically “cookies0.db”
  3. Restart the desktop client. The wizard should begin with the “Setup the Nextcloud server” dialog. When you enter the server URL (e.g. the untrusted certificate dialog will be displayed showing the content of the certificate for which no issuer could be found. Click Cancel.
  4. Click “Configure client-side TLS cert” and the “SSL client certificate authentication” dialog will display. Browse to and select your desired client pkcs12 certificate, and enter its password in the provided box. Click OK.

You can then complete the rest of the client/server connection dialog as normal.

Of course the above completely resets your client, and you must re-configure all of your sync connections.