Help! For the first time ever, I've had an upgrade fail. After I logged into the upgrade system and started, it immediately showed a page saying "Safari can't open the page "https://www.concertina.net/forums/admin8600/?app=core&module=system&controller=upgrade". The error is "FetchEvent.respondWith received an error: ReferenceError: Can't find variable: reject" (WebKitServiceWorker:0)"
Now it's stuck. Even going back to the admin main page and trying again, the same thing comes up every time. And I don't see a way to stop the process, so my forums are now stuck offline.
Any ideas? I cleared the cache on the Support section of my admin, but that's all I can see to do. No other errors are showing.
Thanks,
Paul