Steps to reproduce the issue

Please go to official demo site and scroll down to the "Quick Test Drive" heading. Click "Launch Test Drive" button.

Expected result

Usable backend and frontend display with all features.
A few days ago, I have tried that with the previous J!3.6.5 and it worked like a charm.
3.7.0 does not work as expected. See below...

Actual result

Content/Articles manager is missing. Had to use Extensions manager and "Discover" action to re-install articles manager. But Frontend still throws "404 Component not found"?!
Database not up-to-date. Had to Click "fix")
Warning: PHP temp directory not set.

System information (as much as possible)

J! 3.7.0 demo site
powered and set up by siteground (?)

Additional comments

Also tried Joomla Update - re-install. No differences.
I tried the demo two times, from mobile and desktop devices.

PS: I was not sure where to report this issue. Please, delete or move it if this is the wrong place.