I installed the plug in in my multisite network and it installed properly and when I tried to use it on the main site it worked great. The problem came when I tried to log-in to any of my other sites, I got the following error:
"Fatal error: Call to a member function add_cap() on a non-object in /home/content/92/8420892/html/wp-content/plugins/duplicate-post/duplicate-post-admin.php on line 43"
I then network de-activated it and activated it only on the main site and it worked properly.
I tired to activate it on one of the other sites and I got the same fatal error.
Thanks for your assistance.