Parallels 8 Will Not Load USB Drivers

I have an older Macbook Pro running Mac OS El Capitan. After installing my Parallels 8 a window pops up saying the necessary usb driver could not be opened. I tried the solution posted on the Parallels support page but it did not work. Is there anything else I can do to remedy this?

 

Hi, actually Parallels Desktop 8 is not supported anymore, but if you send us a screenshot of the error message which you got, we will try to help you.