Please help , old lightroom catalogue from 3 years ago will not open in new version

... and since rebooting my computer and downloading the latest version of lightroom i cannot open the files anymore ...

Why can't you open the files anymore? What steps have you tried to open these files? Please be specific and detailed. Please describe what happens in detail. If there is an error message, what is the excat unedited word-for-word error message?

Off topic, but that folder named Backups, is that where you store your LrC catalog backups?

https://helpx.adobe.com/lightroom-classic/help/back-catalog.html

How are you trying to open the catalog?

Are you using File> Open in Lrc, or double-clicking the catalog file in the File explorer?

And what happens when you try? Please provide details.

You seem to have a lot of catalogs, which has a number of disadvantages. Most of us only need one catalog.

You can merge all your catalogs into one by opening one of them, and then go to File > Import from another catalog, and repeat this for all the catalogs.