To me, (not on MU), it occurs when your’re viewing the site without being logged-in. Because when a user isn’t logged in the Global $wp_roles is empty.
As a workaround, i had edited the user-role-editor.php,
@line: 181 you’ll have the ure_init() function.
inside of it, the test for: if (!$role->has_cap(URE_KEY_CAPABILITY)) {
i’d put that entire block inside a if, to test if we had a user logged in.
That block of code is unneeded at all. My fault. I left it after some experiments with new functionality.
if (!$role->has_cap(URE_KEY_CAPABILITY)) {
...
}
You see that the action inside is commented. Just remove it yourself or download updated user-role-editor.php from this link
http://www.shinephp.com/wp-content/downloads/wordpress/plugins/user-role-editor-3-7-fast-fix.zip
and replace this file inside user-role-editor plugin folder.
Your feedback about testing results is very appreciated.
YEP it works now 🙂 thanks Vladimir!