In order to get a crash report, you need to see the "Something went wrong..." window after restarting RapidWeaver.
If you don't see this window, then wait for the crash to occur again.
i at the bottom of the window after "An anonymous system profile will be sent". A new window should appear.
The information from this window that is most important is the contents of the Exception and Crashes tabs. Select one of those tabs, the copy the content into an email. Then do the same with the content of the other tab. If one or the other is empty, that is fine. Just send what is available.