In Nautilus Files, Double-clicking to Open with default application does nothing. Right-clicking and clicking on Open with the default application does nothing. Changing the Preferences to Single Click to Open Items and then single-clicking also does nothing.
The only way to open a file is to right-click and then Open with Other Application, and then select the default or another application.
Fresh install of Ubuntu 18.04
Reinstalling nautilus didn't help, unfortunately. Same behavior. Tried all the solutions in this thread (except installing Nemo) Can't open desktop folders by double-clicking on Ubuntu 17.10, nothing helped.
I finally installed Nemo from the Ubuntu Software Center and it works great. (This is a workaround, not a real solution, so I'm not calling it an answer.)
