There´s a typo on french´s localization file, here: java/org/apache/catalina/loader/LocaStrings_fr.properties Should be: LocalStrings_fr.properties ^Here
Thanks for the report. That issue went all the way back to Tomcat 4. I have fixed in for 4.1.x (will be in 4.1.40 onwards), 5.5.x (will be in 5.5.28 onwards) 6.0.x (will be in 6.0.19 onwards) and trunk.