In Arduino IDE the serial port is greyed out and COM 1 i shown in the window There is no way to communicate trough serial connection. Dont know if this is a Arduino Bugg or a bugg in Bionic Beaver. The application worked in 17.10 Artfull.
This bugg is reported and a fix is awaiting an upload in debian
Fixed the NullPointerException with Java 10 caused by the null java.ext.dirs system property (Closes: #896929)
Its not a Arduino only problem but affect serial connections in general.
Tested Pronterface and there is no serial connection to 3D printer.