We slipped a broken profile page to the release, that would be on me, sorry about that!
Luckily, this is something that can be fixed on-device. In order to do it, however, you have to be familiar with Terminal, devel-su and text editing:
devel-su nano /usr/share/harbour-whisperfish/qml/pages/ProfilePage.qml
Go to line 281 and edit it like so:
From: visible: numericFingerprint.text.length > 0
To: visible: numericFingerprint.text.length > 0 && !isOwnProfile
Then comment out (or remove altogether) line 278:
From: visible: !isOwnProfile
To: // visible: !isOwnProfile
Save the file and restart Whisperfish. Now you should be able to access the profile page again - this time with the new feature of being able to edit your own name in your profile.