You’ll want to post the errors from while you’re still on the reviews or lessons page. I think the error you posted above is from while you were on the forums.
I’m still using my version, and it’s still working fine. Have you clicked on the scales on the left/right to select which sort priority you want?
On the lesson page, the interface may need to be expanded if it’s minimized. Look for a [+] along the right edge of the screen, and also try scrolling down in case it’s just farther down the screen. (That may sound obvious, but sometimes the layout just doesn’t make your brain suspect that there might be something further down!)
And again, check for errors while on that page.