Check configuration part of easiestml.php
eg)
define('EASIESTML_LANGS','en,es');
// list the language images separated with comma
define('EASIESTML_LANGIMAGES','images/english.gif,images/spanish.gif');
// list the language names separated with comma
define('EASIESTML_LANGNAMES','english,spanish');
// list language - accept_chaset patterns (perl regex) separated with comma
define('EASIESTML_ACCEPT_CHARSET_REGEXES',',');
// list language - accept_language patterns (perl regex) separated with comma
define('EASIESTML_ACCEPT_LANGUAGE_REGEXES','/^en/,/^es/');
// charset in Content-Type separated with comma (only for fastestcache)
define('EASIESTML_CHARSETS','ISO-8859-1,ISO-8859-1');
With above setting, the link will be
"?easiestml_lang=en"
or
"?easiestml_lang=es"
Anyway, use [ mlimg] tag instead. (remove space after [)