Floor has disappeared

Hello. I have just finished adding most of the parts to my model and the floor has disappeared. I have tried redrawing it back in underneath but to no avail.
Any advice on how I can get it back? I don’t want to lose anything I have done as it has taken me ages.
Thanks in advance.
Happy to share it with anyone who wants to take a look but don’t want to add it to the forum.

Can you upload your skp file?

That will help us in helping you.

@LG_me, please correct your profile!
Incorrect profile information means guessing what you are working with.

I will dm it to you now. Thank you.

What is incorrect? Sorry I don’t understand