Several users of CloverETL Designer 3.1 on Mac OS X platform reported issue with stability and occasional crash.
It is mostly experienced during manipulation with outline view or metadata editor. We are intensively working on fix for this issue, which seems to be connected with Eclipse 3.6.2 or newer (the crash occurs in native SWT code).
One possible workaround for now is to use eclipse 3.6.1 or older which does not seem to suffer from this. This problem seems NOT to occur on Windows or Linux platforms.
We apologize for any inconvenience. Stay tuned - we will inform you about the progress.
CloverETL Team