In Cubase 12 and earlier versions, it was possible to deactivate the Hub in Preferences → General. When that was done, the Hub would no longer be shown when Cubase was opened. Instead, projects could be opened or created with the Project Assistant dialog. In Cubase 13, it is no longer possible to disable Hub in this way.
As reference to deactivating hub is not in the Cubase Pro 13 Operation Manual, whereas it is in the Cubase Pro 12 Operation Manual, I presume this is a feature, not a bug. If so, what does appear to be an inaccuracy in the Cubase Pro 13 Operation Manual is that in the Opening Recent Projects section, it still says
In the category bar of the Hub or the Project Assistant dialog, click Recent, select a
project from the projects list, and click Open.
That’s the only reference to the Project Assistant dialog in the manual.
I did not like the Hub in older Cubase versions, so I deactivated it and used Project Assistant instead. However, I have found what seems to be a satisfactory workaround in Cubase 13. In Preferences → General, instead of Deactivate Hub there’s a new Show News in Hub option. I disabled that. What’s left in Hub is much the same content as in the old Project Assistant, but in a slightly different format.
I take it you mean the Quit Cubase button, bottom right on the opening Hub window. Yes, when closing the window and Cubase with a mouse, it’s disconcerting, as there is no standard application close button at top right. However, in Windows at least, the two standard close application keyboard shortcuts still work: Alt+F4 (works on the vast majority of Windows applications); and Ctrl+Q (works on those Windows applications, such as Cubase, where the the developers wanted to also implement an Mac-like keyboard shortcut.).
For what it is worth, with a mouse, you can still quit from the opening Hub window from the File menu on the main menu bar. But that’s even clumsier. Once you open a project, the standard close button is back.
Martin, I had a hard time getting back to the hub. if I closed the project I had to fiddle around in my taskbar, right-clicking and closing there then the hub would appear., then I would have to press Quit Cubase, at lot of clicks to get there. The CTRL+Q shortcut as suggested is the way to go, so if I just remember to do it I am good now