creates script error while cdn is not used

[thehelloworld007]

$.get( ./languages/${file}.klc).done((data) => {
handleSuccess(data);
}).fail(() => {
// No local languages, try the CDN.
$.get(${CDN_LANGUAGES_DIRECTORY}/${file}.klc, (data) => {
handleSuccess(data);
});
});
while being used in sub urls it creates script error, suppose the ./languages is creating the issue.