Mnemonic should be displayed.
Mnemonic field is empty.
Client version: 3.0.0 (Ubuntu)
Operating system: Ubuntu 20.04
OS language: US English
Qt version used by client package (Linux only, see also Settings dialog): n/a, installed via official deb repository
Client package (From Nextcloud or distro) (Linux only): nextcloud-desktop 3.0.0-20200821.171045.ff175088a-1.0~focal1 amd64
Installation path of client: /usr/bin/nextcloud
Nextcloud version: 19.0.1
Storage backend (external storage): Local file storage (default), s3 via minio

Make sure that before you open an bug report:
Re-open the issue once you have logs. Thanks!
It looks like the issue is that end-to-end encryption on my nextcloud v 19.0.1 is not installed, but the client tells me it is supported:

Thank you for pointing me towards the logging functionality of the client!
This looks like the relevant part, in which the client recognizes no e2e is available, but still draws the button:
2020-08-27 10:15:02:301 [ info nextcloud.sync.credentials.webflow ]: request finished
2020-08-27 10:15:02:301 [ info nextcloud.sync.clientsideencryption ]: Initializing
2020-08-27 10:15:02:301 [ info nextcloud.sync.clientsideencryption ]: No Client side encryption available on server.
2020-08-27 10:15:02:302 [ info nextcloud.gui.account.state ]: AccountState connection status change: OCC::ConnectionValidator::Undefined -> OCC::ConnectionValidator::Connected
2020-08-27 10:15:02:302 [ info nextcloud.gui.account.state ]: AccountState state change: "Disconnected" -> "Connected"
2020-08-27 10:15:02:302 [ info nextcloud.gui.activity ]: Start fetching activities for "鈻柈鈻柈鈻柈鈻柈鈻瓳鈻柈鈻柈鈻柈鈻柈"
2020-08-27 10:15:02:302 [ info nextcloud.sync.accessmanager ]: 2 "" "https://鈻柈鈻柈鈻柈鈻柈/ocs/v2.php/apps/activity/api/v2/activity?since=0&limit=50&format=json" has X-Request-ID "b273807e-2e35-4723-a96f-b2a3195b6a1d"
2020-08-27 10:15:02:302 [ info nextcloud.sync.networkjob ]: OCC::JsonApiJob created for "https://鈻柈鈻柈鈻柈鈻柈" + "ocs/v2.php/apps/activity/api/v2/activity" "OCC::ActivityListModel"
2020-08-27 10:15:02:302 [ info nextcloud.sync.accessmanager ]: 2 "" "https://鈻柈鈻柈鈻柈鈻柈/ocs/v2.php/apps/notifications/api/v2/notifications?format=json" has X-Request-ID "bc9e99fe-26fa-491d-96e8-b4d92043f12b"
2020-08-27 10:15:02:302 [ info nextcloud.sync.networkjob ]: OCC::JsonApiJob created for "https://鈻柈鈻柈鈻柈鈻柈" + "ocs/v2.php/apps/notifications/api/v2/notifications" "OCC::ServerNotificationHandler"
2020-08-27 10:15:02:303 [ info nextcloud.gui.account.settings ]: Account "鈻柈鈻柈鈻柈鈻柈@鈻柈鈻柈鈻柈鈻柈" Client Side Encryption false
Let me know if this is enough information for you to continue.
the client recognizes no e2e is available, but still draws the button:
The good news is that this is fixed and today I will be tagging 3.0.1 with the fix for it (PR #2280)
Anyhow thanks for the logs :)
Most helpful comment
The good news is that this is fixed and today I will be tagging 3.0.1 with the fix for it (PR #2280)
Anyhow thanks for the logs :)