Whoaaa!!!
I got same issue. Installed this plugin from the WP plugin interface and it crashed the site.
“Fatal error: Call to undefined function register_uninstall_hook() in /wp-content/plugins/user-access-manager/user-access-manager.php on line ####”
I deleted the plugin from the /wp-content/plugins/ folder, but now when I try to access pages on the site it prompts me for username/password.
What can I do to stop this???
I;m using WP 2.7.1 with no other authentication type plugins.
Thanks.