Buggy and confusing UI in the "Upgrading the system" dialog

I encounter a problem in the Upgrader with the message:
“Upgrading the system
Your Tails device is being upgraded…
For security reasons, the networking is now disabled.
[static progression bar all in blue]
[validation button]”

- If I validate, the window disappear and I have no feedback until the upgrade is complete.

- The progression bar doesn’t work.

Attachments

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Parent Task: #14754

Related issues

• Blocks #16209

Original created by @xin on 16603 (Redmine)