If you click on the desktop you bring the Mac's "Finder"...
If you click on the desktop you bring the Mac's "Finder" application to the front. When that happens the toolbar hides. If you click on QuickBooks icon in your dock (typically at the bottom of the screen) then you'll bring QUickBooks back to the front and the toolbar will show again. The toolbar (in 2013) only shows when QuickBooks is frontmost. It is one of the things we changed in later versions - people coming from Windows computers aren't familiar with this behavior as its more of a Mac thing.
Re: I also have this problem, it disappears or a little bit o...
It is enough to drive a person insane! Why would QB assume users would be happy to have the toolbar down the left side? It creates so much more screen clutter. Sometimes, logging off and then logging back in (as opposed to just closing QB and reopening if you have the "keep user logged in" setting checked) brings the top toolbar back, but I'm not sure if that's a coincidence. And what a colossal waste of time! I am in and out of 8 or 9 other QB files all day, and it never seems to happen to more than one at a time if that helps anyone.
Allow me to help share additional information about the toolbar in QuickBooks.
If you're using QuickBooks Desktop for Mac, Mac toolbar will always show at the top of the screen. However, if the icon bar is missing, you can try closing the toolbar and then reopen it. In addition, you may also follow the workarounds or steps provided above.
On the other hand, if you're using QuickBooks Desktop for Windows, you have the option to hide the icon bar or show the icon bar at the left or at the top of the QuickBooks homepage by clicking the View menu.