Synology 213 unable to load UTF-8 after DSM 5 upgrade

[JohnTan]

Hi Simon ! Thanks for your prompt response and here is the output :

DiskStation> locale -a
locale: Cannot set LC_CTYPE to default locale: No such file or directory
C
cs_CZ.utf8
da_DK.utf8
de_DE.utf8
en_US.utf8
es_ES.utf8
fr_FR.utf8
hu_HU.utf8
it_IT.utf8
ja_JP.utf8
ko_KR.utf8
nb_NO.utf8
nl_NL.utf8
pl_PL.utf8
POSIX
pt_BR.utf8
pt_PT.utf8
ru_RU.utf8
sv_SE.utf8
tr_TR.utf8
zh_CN.utf8
zh_TW.utf8
DiskStation>