fatal error on marketpress update

I am seeing a fatal error under orders on a store after I updated marketpress: Fatal error: Call to a member function is_download_only() on a non-object in /nas/content/staging/ecraft/wp-content/plugins/marketpress/includes/admin/class-mp-orders-admin.php on line 1078

This order was successful on April 17th. I then updated site on April 19th and now this past order has this error sitting next to it. I then checked to see if I could make a successful new order and I was unable to do so. During the test order, I got an error when marketpress sent me to paypal. the error said validation api credentials are invalid. I then reverted the site back to April 18th before the update. I now have the updated site with the errors on a staging site to take a look at it and try to fix this problem before pushing it back live again. Check out this past thread too as I had significant problems with this same site when I first updated marketpress. I thought I had solved all issues but then this cropped up so I am back to needing help getting this figured out. Here's the old thread that has not been resolved yet,obviously.

https://premium.wpmudev.org/forums/topic/getting-fatal-error-after-marketpress-update#post-1059053