If you add all your current info into it is should be, but if you do that I will no longer be able to do anything, as I won't know the original status.

You could upload a new one, and rename the old one to config.php.old, so you won't loos any original info.

Ok I am try to do so.
if problem persist then I'll give u ftp info
but why it happend?

Editing files with notepad will sometimes add a UTF8bom in the files, causing you issues, that is why it is best to edit them with notepad++

if I edit it again with notepad++ it will be ok?

if I replace it with new config.php the forum will run normally?

If you do a new config file, and add all your info into it from the old file, with notepad++ it should be ok.

do you means I must copy old config.php data into new?

No not the data, any changes that are in there such as,
$config['Database']['dbname'] = 'XXXXXXX';
$config['MasterServer']['username'] = 'XXXXXXX';
$config['MasterServer']['password'] = '[XXXXXXXX]';

I am sending u FTP info plz solve the issue.

Did you make any changes to the file other than adding and removing the afore mentioned line?

I did not change these area.

--------------- Added [DATE]1394387894[/DATE] at [TIME]1394387894[/TIME] ---------------

no I did not any change just put that line that you give.
after error I remove that line.

--------------- Added [DATE]1394387929[/DATE] at [TIME]1394387929[/TIME] ---------------

FTP info send by pm to you plz check and solve the issue.