The 'Convert Class To Java' menu item (from the main menu) can cause an exception when called on a class that is already Java.
Normally, the menu item should be greyed out if the class is Java. The following sequence leaves the item enabled for a Java class:
- select a Stride class
- select 'Convert to Java'. Confirm.
(Conversion happens, class remains selected; menu item remains enabled.)
- select 'Convert to Java' again.
Possible fix: either disable menu item after conversion, or de-select class after conversion.