The Collaborative for Croquet should be good to go, again. Get the new download.
We’ve lengthened the fuse on self-destructing deleted stuff and improved the error logging, and have not seen further “no such object” errors. (Except for one person who was using an older version. This beta release doesn’t check your version, but I could tell from the error report that it was something we fixed two versions ago.)
Also, the Macintosh VM that was included in the last download had gotten miscopied somewhere along the chain. Testing the new .zip confirms that it works on Mac and Windows. (Linux folks will have to test on their own.)
Anyway, this beta version still doesn’t have anything to reset itself if someone does manage to crash things, so if it takes longer than a minute or two to connect, let us know.