cannot type Vietnamese

Could you tell us which of the various Vietnamese keyboards supplied with OSX you are talking about, and what exactly is not working with it?

I had the same issue. Tried to add and remove input sources such as Simple Telex, Vienamese, U.S. and it worked.

Hi,

I do as you said, but it doesn't work at all. Don't know what to do next 😟.

I found a solution, maybe you have to disable "Secure Keyboard Entry" in default terminal app or iTerm (if used).