Just for others, I see warning (see below) when I open the project but the schematic is fine now.
Warning maeeage (ignore it) :
This schematic was made using older symbol libraries which may break the schematic. Some symbols may need to be linked to a different symbol name. Some symbols may need to be “rescued” (copied and renamed) into a new library. The following changes are recommended to update the project.
Thank you t3p3tony, good job!
PS: The kicad version I use is current version for Ubuntu 20.10 .