I have the same problem ('though using standard Oracle Java 6) and I've been wrestling with it now for a day or so, however I haven't come to any firm conclusion I'm afraid.
Originally Posted by vondie
What I can say is that I can re-create the problem easily simply by first of all deleting my target folder and then running my JUnit tests. Deleting the target folder allows Roo to start (I get the problem whether I use STS or not) but once I run my unit tests and restart Roo, Roo gives the error NativeConstructorAccessorImpl.newInstance0.
So I have a work around but in case deleting the target folder doesn't work for others I've also noticed that during my upgrade from Roo 1.2.0.M1 I had to delete all the generated aspect J files for my domain objects only (forcing Roo to regenerate them from scratch) and if that doesn't work the other thing I did was to start again with a new pom.xml (I created a temporary project with the same top level package and set-up the same persistence and web settings) and manually copy all of your project specific dependencies etc.
Some combination of the above worked for me and I hope it works for others.