A new version of Login as User - Joomla! component has been released.
+ Added ! Removed ^ Changed # Fixed
14-Apr-2016 : v3.0.3
# Bug Fixed: An error 404 (0 - Invalid address) is displayed after upgrading to Joomla! 3.5.1, after clicking on the link "Login as _username_". [Thank you, Lisa Keyser]
(view the full changelog)