Upgrade link shows blank page

Following the ‘one-click browser upgrade’ link from emails alerting me to ‘New Discourse version, upgrade available’ simply leads to a largely blank page, as shown in image

[url is /admin/upgrade ]

Clicking the processes tab works in sense that it shows the actual processes, but then clicking back to versions tab just leads back to same blank page.

This has been true of last four or five ‘new version’ emails. Was hoping it would just solve itself but it hasn’t yet.

Any suggestions?

[I found https://meta.discourse.org/t/automated-upgrade-page-not-showing/63194 but there is no mention of whether it was ever actually resolved.]

SSH in and execute these two commands

cd /var/discourse
./launcher rebuild app

That worked. Thanks.