How do I open _1.zip files?

P.S. Ive installed 7 Zip

please don’t double post in off topic places.

https://forums.sketchup.com/t/sketchup-2024-crashing-too-often/273257/47?u=ateliernab

to extract zip files, some softwares will automatically create a folder with the good stuff in it, some will just open the zip and you’ll have to copy what you need.

from your screenshot, it looks like you need to click on the sketchup file, copy it, and paste it somewhere else, maybe your desktop.

or try winrar.
https://www.win-rar.com/start.html?&L=10