

The true fix required both of the suggestions above and then some: I'm on macOS on a MacBook Pro and no amount of uninstalling, re-installing, updating or playing with preferences fixed this.I had even used the various Window tips to see if that would do the trick (as I sometimes have an external display). Is it working? Then there is something off in your first account, and it would require much deeper digging to figure out what that is. Use a different account on your Mac (you may have to create a new user account first) and try to start Reader. If you are still not able to use Reader, then it's time to see if it has something to do with your user account. If that makes Reader behave again, then good, if not, you an rename the plist file back to it's original name after you remove the new plist file that Reader just created (again, do that after you shut down Reader). You will then see the "Library" item - select it and then navigate to Library/Preferences/ Here you should find a file named - rename that file to e.g. To see that in Finder, you need to hold down the "Option" key and then go to the "Go" menu. On Mac OS, these are stored in a plist file in your Library folder.

If it's still not working, I would remove Reader's preferences.

If Reader starts up after that, then you are done. Sometimes that helps to resolve issues that are caused by e.g. Here are the things I would do: Reboot your computer. Unfortunately, Acrobat/Reader on Mac OS does not come with the repair option the the Windows version has, and Adobe also does not have the Cleaner tool that they offer for Windows for us Mac users ( Download Adobe Reader and Acrobat Cleaner Tool - Adobe Labs ).
