Since we're talking about the "com.alibre.rose.RoseException" error, I got it for the first time tonight. I opened a session, created one part and tried to save it. Boom, "Save operation encountered error: 'com.alibre.rose.RoseException. Object reference not set to an instance of an object. Check if failure is due to insufficient disk space or file access privileges." I have over 120 gB of free disk space and I'm logged in as the Administrator, so I don't think that's the problem. Tried to save to another drive, but that didn't work. Can export successfully to a SAT, and STP (AP 214) file, but not to an Alibre STP file. Fortunately, I'm just modeling a purchased part that, hopefully, I'll never have to edit again. I'll just import the SAT or STP model into my assembly and I'll be OK. Guess I was just lucky this time.
I'm running PRODUCTVERSION 11,2,0,11077.
Hope this does get fixed in v12.