arduino ide not starting java error

Hi

strangewise I can not start arduino IDE.

any hints please?

Thanks a lot

arduino
Picked up JAVA_TOOL_OPTIONS: 
java.lang.NullPointerException
	at processing.app.BaseNoGui.onBoardOrPortChange(BaseNoGui.java:679)
	at processing.app.Base.onBoardOrPortChange(Base.java:1317)
	at processing.app.Base$12.actionPerformed(Base.java:1544)
	at processing.app.Base.rebuildBoardsMenu(Base.java:1494)
	at processing.app.Base.<init>(Base.java:275)
	at processing.app.Base.main(Base.java:151)

Which operating system are you using?

Hi,

running 18.04 ubuntu

Picked up JAVA_TOOL_OPTIONS:
java.lang.NullPointerException
at processing.app.BaseNoGui.onBoardOrPortChange(BaseNoGui.java:679)
at processing.app.Base.onBoardOrPortChange(Base.java:1317)
at processing.app.Base$12.actionPerformed(Base.java:1544)
at processing.app.Base.rebuildBoardsMenu(Base.java:1494)
at processing.app.Base.(Base.java:275)
at processing.app.Base.main(Base.java:151)