I get this error when viewing the Adminer page:
2013/10/02 04:11:32 [error] 9610#0: *7629 FastCGI sent in stderr: "PHP Fatal error: Call to undefined function is_user_logged_in() in /home/deployer/sites/mydomain.com/wp-includes/admin-bar.php on line 741" while reading response header from upstream, client: 127.0.0.1, server: mydomain.com, request: "GET /wp-content/plugins/adminer/inc/adminer/loader.php?username=<myusername>&db=<mydb> HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "mydomain.com", referrer: "http://mydomain.com/wp-admin/network/settings.php?page=adminer/adminer.php"
If I deactivate my other plugins and use default theme, it works.
It looks to be related to the use of the "is_admin_bar_showing()" function in a different plugin.
Maybe there is a way to not load the other plugins with Adminer?
These plugins don't throw any errors by themselves.