Once upon a time, every window on a Mac desktop had big, easy-to-click and impossible-to-miss scroll bars that never, ever disappeared.

• Why Does My App Bar Keep Disappearing On My Mac Account

Jan 17, 2020  'Cursor/mouse disappearing on Macbook Air: I'm not sure if it's a glitch in the new Macbook update, but every few minutes my cursor on my Macbook Air keeps disappearing-Try This: Reset the NVRAM. Sometimes, when performing upgrades, the NVRAM becomes manipulated, technically. So reset the NVRAM. All should be back to Normal, afterwards.

Since 2011’s “Lion” update to Mac OS X, however, Apple has adopted an “barely there” policy when it comes to scroll bars.

Indeed, scroll bars on the Mac are now just as wafer-thin as they are on the iPhone and iPad—and in some cases, they may disappear completely when you’re not actively scrolling.

Luckily, it’s easy to get those scroll bars back—not the old, larger versions, mind you, but at least you can keep the Mac’s new, skinny-mini scroll bars visible at all times.

Here’s how:

• Click the Apple menu at the top-left of the screen, then select System Preferences.
• Next, select the General preferences pane; it’s the very first one, up at the top.
• Under the “Show scroll bars” heading, you’ll find three options: “Automatically based on input device,” “When scrolling,” and “Always.”
• Go ahead and select that last “Always” option. You’re done!

Bonus tip

Wish you could get the missing scroll bar buttons back, too? You can’t, unfortunately, but you can always use your arrow keys for precision scrolling.

Each time when users start Safari, toolbar missing. Users need to go to the View menu to turn it back on.
Its really annoying one. So how to keep the menu bar from disappearing?
Fix 1:-
If your navigation bar was gone, Press Command + L and quit the the browser (Command + Q). Then reopen your browser. navigation bar should back.
Fix 2:-
From the Safari View menu, unclick Enter Full screen option.
Fix 3:-
Close Safari and restart it.
Fix 4:-
On the top right corner, right click expand all double arrow and unclick “Hide toolbar”.
SEE ALSO :How to fix Safari running slow on Mac OS X Yosemite
Other Solutions:-

Why Does My App Bar Keep Disappearing On My Mac Account

• Uninstall some 3rd party apps and plugins like Cosmopod, SpiceRack and Videobox.
• Go to Applications -> System Preferences -> Display and change the resolution from 1280×1024 to 1152×870.