getting fatal error after marketpress update

Hello, I have been unable to update to any marketpress after 2.9.6 because it would break my site. Now I have a staging site to play with so once I can figure out what is going on, I’ll be able to push it live. Yay…… so in the meantime, I am getting this fatal error on all subsites and can’t get to any sub site dashboard to update their marketpress store. Fatal error: Call to a member function add_cap() on a non-object in /nas/content/staging/ecraft/wp-content/plugins/marketpress/includes/common/class-mp-installer.php on line 903

I already updated the network marketpress settings and disabled the theme and all plugins one by one to see if there was a conflict. Nothing….error still persists. Hoping to finally get this resolved so I can update live and get all the great new marketpress features. I’ve granted access.