I can't save the changes, I have jury help please

When I save the current version of my model, it returns to its original state, I cannot make any changes. random places are deleted how can i fix it

If you save the file as a 2020 version SKP, does it look better?

It does not work. I also tried saving from another sketchup account. I also tried to open it in another sketchup file.

What OS are you using @damlasuskp2?

Can you share what file you do have?