Classic licence reset?

Although you have activated on three machines, I only see information for two of them. Not sure why that is.

When you upgrade an old license, you can then only activate the latest version you have a license for. In your case that’s SketchUp 2021. If 2020 is already activated on a machine, it will continue to work, but you can’t activate 2020 on a new machine.

You did have 2020 activated on another machine. If you can find that one it will still be working.

I have started SketchupPro 2019 on a machine that it was running on 6 month ago. The license was suddenly missimng. I was able to add my classic license and start. But after the 2nd start it told me that the license was used too many times. I do not have access to the old machines. Is there a way of getting my license count reset?