Sketchup File Save As not skb file?

I’m having a problem with Sketchup Pro 2021. Whenever I “Control Save” my file, my backup file saves as an Adobe Illustrator file. Why does it do this, and how do I change it?? It won’t save as an SKB file nor open up sketchup when I double click on it. When I try to open this “Adobe Illustrator backup file,” a bunch of binary code opens up. Is there a way to change the saving program or backup file location?

In your Windows settings:


.skp should be associated with Sketchup, .skb shoud have no default file selected.

Thank you!!