Hi and welcome to Arturia forums.
The V3 version have a new preset system. That's why you can't import old presets in V3 just like that.
You need to own and have your old application installed with your old presets imported. Then you can use Arturias preset updater/ converter to update the old presets to the V3 version.
You can keep running the 2 applications alongside each other, but also uninstall the old applications after the conversion if you need to.
Please read this:
https://www.arturia.com/faq/vc5presetupdater/preset-converter-general-questionsThe preset updater is availble on Arturias download page here:
https://www.arturia.com/support/updates&manualsIf you have'nt sold your old V2 applications, then you still own them. But was it V2 15 years ago? I assume V1 had the same preset system.
The preset updater is named VC4 preset updater though.