Undefined variable: pagenow in general-functions.php

The cause of the problem is that the capability checking condition is not using a curly brace/bracket: if ( current_user_can( 'update_core' ) )

Code Correction:

function bpsPro_login_security_password_reset_disabled_notice() {

	if ( current_user_can( 'update_core' ) ) {

	global $pagenow;

		if ( 'profile.php' == $pagenow || 'user-edit.php' == $pagenow || 'user-new.php' == $pagenow ) {
			$BPSoptions = get_option('bulletproof_security_options_login_security');		

			if ( $BPSoptions['bps_login_security_OnOff'] == 'On' && $BPSoptions['bps_login_security_pw_reset'] == 'disable' ) {

				$text = '<div class="update-nag" style="background-color:#ffffe0;font-size:1em;font-weight:bold;padding:2px 5px;margin-top:2px;"><font color="blue">'.__('BPS Login Security Disable Password Reset Frontend & Backend is turned On.', 'bulletproof-security').'</font><br>'.__('Backend Password Reset has been disabled. To enable Backend Password Reset click ', 'bulletproof-security').'<br><a href="admin.php?page=bulletproof-security/admin/login/login.php">'.__('here', 'bulletproof-security').'</a></div>';
				echo $text;
			}
		}
	}
}

Important Note: After you are done debugging be sure to turn off WP_DEBUG in your wp-config.php file. Debugging should only be turned on for temporary debugging and should not be turned on/enabled permanently.

This will be corrected in the next BPS version release.

Thanks for your reply. Site is currently on development, this is why we have debug mode activated.

Ok, but remember that even during development you do not want to leave WP_DEBUG on permanently. Some plugins and themes do not work correctly when you are in debug mode. So you want to switch back and forth between on and off and not leave WP_DEBUG on permanently. In theory all plugins and themes are supposed to still work correctly when WP_DEBUG is turned on, but in reality that is not always the case.