I started the installation of a program on a MacBook Pro laptop running OS X Yosemite (10.10.5), but then switched to a Terminal window. When I wanted to switch back to the installation window I could no longer find it in the OS X dock at the bottom of the screen, nor could I see it by cycling through open windows with the Command-Tab keys, nor did I see it when I clicked on the Apple icon at the upper, left-hand corner of the screen and looked for it under Force Quit. When I tried to restart the installation by clicking on the Apple Disk Image .dmg file, nothing appeared to happen. I was able to find the invisible window by hitting the F3 function key on the keyboard, though. I could then see the hidden DiskImages UI Agent window that I hadn't been able to locate previously. I was able to click on it and bring it to the foreground where I could proceed with the installation.
[ More Info ]