Okay, people immediately found bugs with the 3.1 release (and obvious bugs as well I really should have tested it more).
So now 3.1.1 has been uploaded, the two bugs should be fixed now. With a bit of luck, I haven’t made any other serious mistakes.
For those wondering, the Asset Store submission is pending.
Changelog (updated version will be uploaded in a minute): http://arongranberg.com/astar/docs/changelog.php
[EDIT] Version 3.1.1 is now available in the Asset Store as well.