Fontconfig warning

Hello to all forum,

I imported a large element geometry in Salomè and it went ok.

When I switch to mesh module and click on "wiew", It crashes and on the shell it get the following error:

Searching /Kernel/Session in Naming Service ++++++Fontconfig warning: line 32: unknown element "cachedir"
Fontconfig warning: line 33: unknown element "cachedir"
Fontconfig warning: "/etc/fonts/conf.d/00-cache.conf", line 6: unknown element "cachedir"
Fontconfig warning: "/etc/fonts/conf.d/00-cache.conf", line 7: unknown element "cachedir"
Fontconfig warning: "/etc/fonts/conf.d/80-delicious.conf", line 18: invalid match target "scan"


I have suspicion this is a Linux problem.
Does anybody have any idea?

P.s I am using PCOsLinux distro.

Thanks in advance.

Luigi