Problem Illustrator 24 does not support the old PANTONE libraries
I tried to follow your guide: https://helpx.adobe.com/illustrator/kb/pantone-plus.html, that I always used to insert the old PANTONE libraries and have a conversion to CMYK instead of LAB and in this version it doesn't work.
I contact the online chat and they replied that this thing with ILLUSTRATOR 24 is no longer supported, and it is absurd.
I also tried to install the prereleas 24.0.1 but it doesn't work.
I can't work without this.
This is mind-boggling. C'mon Adobe, we pay you a fortune. Files from last month now look like sh*it now that I upgraded???
Also If I open some file with pre-saved old Pantone Color (with CMYK-definition), the new CC2020 show it as Spot color with CMYK-definition mode.
But if I copy-paste object with this color to another file (new 2020 of old CC-generated file), the color change to "Book" with Lab-definition without any warnings.
Thi is a big problem. Because You can made many changes in file and all stay correct, but one Copy-Paste change the color.