Problem With PlugIn

I was attempting to install the asides plug in mini posts 2. When I activated it
this came up
Fatal error: Call to undefined function: register_sidebar_widget() in /home/findasec/public_html/loveblog/wp-content/plugins/miniposts2.php on line 533
Now I can’t even get into the admin panel. I deleted the php file etc hoping that would help.

Can someone help me?

Note: I was able to finally get into my admin. I’ll try this again…