I had a box running 3.0.14 with a database I wanted to preserve, so I exported it, moved the .gz to my new box, setup 3.1.0 (cause why not), and tried to import the database. I get the following error:
Impossible to remove the last cluster of class 'ORole' drop the class instead
When I attempted to do just that [“DROP CLASS ORole”] the console just hung. Trying this various times, sometimes the process could be terminated, sometimes it started getting various Java out of memory errors and had to be kill -9’d from another window.
I finally downloaded 3.0.14 on my new box and was able to import with no problems. Let me know if you need more info to repro.