Fatal error: Call to undefined function mb_strtolower()
Reson for this error is mb_strtolower not installed on the server. Do a google search for the error you will see it.

Also you phpinfo do not show mbstring

phpinfo()

See

phpinfo()

have following entry

mbstring
Multibyte Support enabled
Multibyte string engine libmbfl
Multibyte (japanese) regex support enabled
Multibyte regex (oniguruma) version 4.4.4
Multibyte regex (oniguruma) backtrack check On