lubuntu 16.10 tool serial port disabled

Hi
New with arduino and ubuntu ; Arduino Mega 2560 and LUBUNTU 16.10
Tool, serial port is not enable so i can't change com1 for com3
in /dev/tty.. there are only tty, tty1, tty2 .. tty63, no ttyACM0
What can i do
Thanks for any help

Try this "Diagnosing Arduino Problems in Linux".

Some good information in this.

Thanks a lot.
I found the problem; it was due to the modemmanager service
The link “Diagnosing Arduino Problems in Linux | Majenko's Hardware Hacking Blog” is very usefull and very clear.
thanks again.