xml - Executing php sctipt with cyrilic gives internal 500 error -

i trying tackle issue since quite time.with few words, add additional node existing xml structure (using simplexmlelement) cyrilic word.for example :

$mainnode->addchild('topic','Город'); 

i tried several tricks , functions iconv etc, each time try execute script in server returns

 internal 500 server error 

message, if delete line, executes fine.any ideas welcomed

just experiencing similar issue, guess happen type of scripts, arabic,chinese etc.

it turned out

default_charset 

in php.ini file left empty after putting

default_charset = "utf-8" 

now works fine