diacritic characters does no work in Portuguese language
Please describe more - what you can not write?
Also, what is your operating system? Is it a problem in your keyboard?
Sorry! I think the problem is from Ubuntu 16.04. Keyboard configuration was correct, but I've fixed the bug with a command line on Terminal: setxkbmap -model abnt2 -layout br
Thanks for following up. Glad you’ve found a solution!