I changed computers and filing ideas. Had thousands of photos shot on various Leica D-lux, Nikon's etc. between 2006 and 2022, RAW, RWL, NEF. Created a new catalog after updating to the latest verson of LR. Started the import with "convert to DNG" only the 2006 photos got converted, the rest are renamed (with date etc) but RAW, RWL, NEF. Any ideas what went wrong?
I think what you did wrong was to start a new catalog. When you upgrade to a new version of LrC, you should be able to use the previous catalog — the upgrade process makes a copy of your previous catalog, and then upgrades the copy to work in the new version of LrC. (If you didn't get an option to upgrade, then double-click on the previous catalog .LRCAT file in your operating system or use File->Open Catalog in LrC on the previous catalog file)