What happens when trial expires

hi guys just upgraded my sketchup to 2021 and just sva e my models to 2021 version but i just realize what happens when the trial expires can i still use sketchup 2021 or will sketchup cant be used anymore?

2021 will stop working unless you buy a license, so back save your files to whichever version you currently have and they will work fine.
File/Save As and adjust the dropdown to your version

What Box says would be the thing to do. I’m just adding a note to say that the Open Newer Version extension, that would usually be a good option, doesn’t support 2021 files. There is reason to think that it never will, but @eneroth3 may have an opinion about that.