Disappearing Tabs after changing or closing windows

[Matt.WestSU7H9]

Lets see if anyone else has this issue. So I have 2 windows open. File on the left is the main assembly. File on the right is the imported (and saved/vaulted/checked out) part that I want to add to the assembly. I drag the part name to the assembly file, then close the file on the right. I'm not going to edit it, so no need to have it open. Once I close that right window, the left window auto maximizes to show the fill assembly.

Problem is, some of the File Tabs on the top of the screen DISAPPEAR! 

In order to correct this I have to minimize the window, then click on the lower tab to maximize it again, and suddenly POOF... they're magically back like normal.

I'd call that a glitch.

Any ideas?

[johnsonshiue]

Hi! Try right-clicking on the ribbon panel -> Show panel -> check the ones you want to see.

Many thanks!