Produced Deprecated Error

Plugin produced the following, preventing me from gaining access to the login page to the admin panel.

Deprecated: Methods with same name as their class will not be constructors in a future version of PHP; SMTheme has a deprecated constructor in /home1/wvtwopac/public_html/wp-content/themes/monamour/inc/library.php on line 2

I couldn’t do anything to rid my site of the error until I finally deactivated, but now it won’t actually delete, so I can’t get rid of it completely.