Antonio C. you won't be able to import screens into a file that is not a Relume figma kit going forward. You can duplicate the kit and import, and then copy/paste the screens into your previous project.
Another option would be to duplicate the latest figma kit, and transfer your projects existing variables into this file and then copy/paste your previous screens into this project.
https://www.figma.com/community/plugin/1256972111705530093/export-import-variables
We've already done some rapid updating here to provide some level of backwards compatibility but in order for our figma plugin to work properly we need predictability in the file and having a bunch of different figma files just won't be possible anymore, unfortunately.
