I’m getting the same error :(. A temporary workaround is to edit that mentioned line 153 to
'email' => $user ? $user->get( 'user_email' ) : ''
But that can’t really be intended.
When I create a file called ‘single-event.php’ in my custom template, nothing changes. Where exactly is this file supposed to be created?
For now, testing on post_type works at least. Thanks!
I managed to get rid of this message by looking at the code, and fixing an (apparetly) little bug.
On line 876 of em-install.php, there is a call to a function named is_set, which looks like it should have been isset. By changing this, and forcing the upgrade by adding true || to the if struct on line 17 it managed to complete the update, and get rid of the message.
