[$interpolate:interr] Can't interpolate: {{ vm.TL('form.username_placeholder') }} ReferenceError: langs is not defined http://errors.angularjs.org/1.6.3

[$interpolate:interr] Can't interpolate: {{ vm.TL('form.username_placeholder') }} ReferenceError: langs is not defined http://errors.angularjs.org/1.6.3/$interpolate/interr?p0=%7B%7B%20vm.TL('fo…e_placeholder')%20%7D%7D&p1=ReferenceError%3A%20langs%20is%20not%20defined at vendor.bd1dc7a8.js:3 at Function.yf.interr (vendor.bd1dc7a8.js:7) at l.exp (vendor.bd1dc7a8.js:5) at Object.pre (vendor.bd1dc7a8.js:5) at vendor.bd1dc7a8.js:3 at va (vendor.bd1dc7a8.js:5) at n (vendor.bd1dc7a8.js:4) at g (vendor.bd1dc7a8.js:4) at g (vendor.bd1dc7a8.js:4) at n (vendor.bd1dc7a8.js:4)