-a- i use the [x] Embed JAVA
feature of the export options dialog.
-b- your file saving seems not processing style
-b 1- pls. save the project first with processing "save as "
what is your sketchbook path in preferences.txt?
-b 2- then press the export button
and that sub dir structure will be under it.
-c- i need to see the terminal window with start command and error msg
as i show you the small one ( ok i snap it with the running application canvas for proof)