It can happen that you accidentally delete a lesson. First, check your trash to see if you can restore the lesson from there.
If this is not the case, please feel free to contact us via the chat in the bottom right corner or email support@lessonup.com. We are happy to assist you! Unfortunately, we cannot always guarantee that we can restore the lesson.
However, if you have distributed the lesson via a class or as homework, we can often look for an earlier version of your lesson.