On almost all Linux systems you should be able to install it directly out of the box without any need for changes. Try this. In the file
fckg/fckeditor/editor/filemanager/connectors/php/io.php
Go to line 247-248 and comment them out as follows:
/*
if ( preg_match(",(/\.)|(//)|(\\\\)|([\:\*\?\"\<\>\|]),", $sCurrentFolder))
SendError( 102, '' ) ;
*/
There may be something in your path that is causing the error.