Unexpected Format File

Hi, I am asking for your great gratitude to help me recover my sketchup files, whenever I try to open it, it’s saying “unexpected file format”. I’ve read from here, that you shall rename it or convert it to skb, put it’s not working on my end. I try importing the file too but it’s not working either, it’s saying "file not found or invalid. I am getting helpless, I am only a student, and I need these files to complete my project. I hope you guys can help me. I would appreciate so much.
INFIRMARY.skp (10 MB)

Please don’t double post. That just creates confusion.

sorry it’s my first time posting