Bug notice with password protect

I'm getting this message on activating the plugin Deprecated: Assigning the return value of new by reference is deprecated in .../wp-content/plugins/protect-selected-content/protect-selected-content.php on line 210
and a notice

The plugin generated 228 characters of unexpected output during activation. If you notice “headers already sent” messages, problems with syndication feeds or other issues, try deactivating or removing this plugin.

What's going on?

[edit]

I've also noticed I'm getting this on posts with password protection:
Notice: Undefined index: psc-postpass_a6c045bd6c9fc542bbc8c2d3c1ac2a84 in ...wp-content/plugins/protect-selected-content/protect-selected-content.php on line 71

[edit 2]

Ok. so I've noticed that when this plugin is active custom fields can't be deleted. I deactivated it. It's very buggy and definitely needs improvement.