There isn't a particular user mistake that I'm aware of, but in some cases they just didn't get set on upgrade, which causes some problems. Visiting the settings page runs a double check on whether the upgrade ran correctly, and updates things if it didn't.
I did make some changes to post publishing actions in this release, but they only had to do with how the actions were expressed, not with which actions are used, so I wouldn't expect any problems there for you.
If you try upgrading again, let me know - be sure to check your settings to verify that they were updated before attempting to publish anything; that might help.