I even replaced "<string>sans-serif</string>" at the fourth line from the bottom of /etc/fonts/conf.d/49-sansserif.conf with "<string>AR PL UKai TW</string>". But the problem persisted.
I even replaced "<string> sans-serif< /string> " at the fourth line from the bottom of /etc/fonts/ conf.d/ 49-sansserif. conf with "<string>AR PL UKai TW</string>". But the problem persisted.