Can't restore Cloudron, nothing seems to happen

[geba]

I'm trying to move my cloudron to a different provider, following the instructions in the Cloudron Docs. After installing Cloudron, uploading the Backup config, and clicking on the "Restore" button, I get to a page with a spinning progress indicator and three dots below ("..."). After that, nothing seems to happen at all, even if I leave it for hours. I don't see any activity in the browser window, I don't see anything happening using journalctl -f, the boxdata and appsdata folders remain empty. I don't really know where to look for any error messages.

Some info that may be relevant:

• The original Cloudron ist at version 7.0.4, and it's on Ubuntu 16.04 (yes, it's ancient, I should have upgraded years ago), on a Scaleway VPS
• On the new server I made sure to also install 7.0.4, and it's on Ubuntu 20.04 (I tried 22.04 first, but Cloudron 7.0.4 wouldn't install due to the wrong mysql version), on a Hetzner VPS
• The backup is configured to use the local filesystem at /backup, Tarball format, no encryption.
• I did copy the complete backup (tarballs of box, mail, 3 apps) to the same location on the new server using scp.
• I did change ownership of /backup and everything in it to yellowtent:yellowtent.
• I tried with and without checking the "dry run" box
• The old cloudron is still running. I would prefer to keep it that way until the new one works. I did edit /etc/hosts to point to the new server on my local workstation (though I doubt that has any influence on the restore process itself).

I don't really know where to investigate or what to try, especially since I can't find any error messages to give me any hint of what's wrong.

Could the mismatch of Ubuntu versions be a problem? I was hoping that as long as the Cloudron version matches, it should be fine.

Is there any place where I might find logs or error messages related to restoring a backup?

Is there any chance that browser settings have any influence (cookies, ad blockers, ...)?

Do I have to stop the original Cloudron?

[geba]

Got it. I found a javascript error using right-click -> Inspect (Q) in Firefox:

Error: $scope.configureBackup is undefined
$scope.restore@https://<IP_ADDRESS>/js/restore.js:290:13
[...]

That finally led me onto the right track, it's a bug that was fixed in v7.1 by commit 7a6a9cdb: https://git.cloudron.io/cloudron/box/-/commit/7a6a9cdbb4374eae9051326a51a4da21409d662a

I manually fixed that line in restore.js on the server and now it seems to work fine.

[nebulon]

Ah great you managed to get this going!