I setup my first b4j app last Year: a simple interface that uses jSerial library for RS comms.
I wanted to use and modify it now but cannot "add" jSerial?
I then downloaded Chat sample and jSerial from here:
The jSerial library allows you to open and communicate with other devices through the computer COM ports. It can also be used to communicate with Bluetooth devices over a virtual com port. (jBluetooth library is now available: https://www.b4x.com/android/forum/threads/jbluetooth-library.60184/)...
www.b4x.com
It's the same ("Are you missing a library reference?").
I copied jSerial Folder to "additional Libraries":
Sorry, I'm not really experienced in this "field" ;-)...
I know that it should be selectable in the libraries tab, but it does not show up @ all.
Strange as last Year when I last setup this app it was working.
I tried on another computer (complete fresh install).
I then moved jSerial files to B4J libraries folder (not additional libraries folder).
Like that it works ?...