Double click does not open files or folders

Question

I have a fresh installation of Ubuntu 18.04, and I have noticed that double-clicking (with mouse or touchpad buttons) does not open files or folders. Single click does select them, but the second click seems to have no effect. If I click on a file or folders and then hit Enter, they do open as expected. Any ideas?

Answer 1

I ran into this problem, the solution is as @singrium outlined in the comments. I am posting it as an answer so that people running into the same problem can more easily find the answer.

Open the Settings app, go to Accessibility, scroll down until you find the "Double-Click Delay" slider, and adjust it to what works best for you.

Apparently, the minimum setting completely disables double click.

Answer 2

in my case,

Settings -> Universal Access and in Pointing & Clicking, turned on Mouse Keys will resolve this problem.