Replacing a key in the website fails

It took me a few tries to get a key into keybase.io's webapp. I did a bunch of different things, but briefly, adding a key when I already had one didn't work. It warned me that only one is allowed, and asked if I wanted to replace it. I said yes, but at some stage I saw a JSON error message in a UI dialog in the browser, saying something about revoke failing.

Sorry to be fairly lame about reporting this, but I did so many things it is all a blur now. Hopefully you can make sense of it.

The report names no source file, test, or reliable reproduction steps. Start by tracing the website flow for adding a key when one already exists, reproduce the replacement attempt, and identify where the revoke error is surfaced; done means replacing the existing key no longer shows the JSON error dialog.

Written by the indexing model from the issue text.