improper interface loaded– unable to use plugin

I have downloaded tried to use, deactivated, deleted, and reinstalled this now three times. each time i get this kind of UI screen

https://ats-sales.com/wp-content/uploads/2013/08/not-working-e1376494972800.png

which is dysfunctional when i try to make selections and save. I dont know why this is happening instead of getting the appropriate UI screen. the only thing i can thing of is that i only have the accordion plugin downloaded not the second file of Nextend that it tells you to have in the installation guide– i cant seem to find it on WP

help?

https://www.ads-software.com/plugins/nextend-accordion-menu/