Why isn't Vue.js working?

Question

JavaScript

Hello.
I'll be honest and brief: I'm a full stack developer for a company. Little experience. I program in PHP and JavaScript. For a company before me (my programmer predecessor) I made an application for Bitrix24 on Vue.js. Now the application has stopped working, instead of text, something like {{lang.departament_label_text}} has appeared everywhere, there are no errors in the console, everything loads fine in the Network tab of the Chrome browser.
I am not familiar with Vue.js at all.
Tell me, please, in which direction to dig?
Of course, I try to read the documentation, but I ask for help to quickly understand Vue.js and solve the problem.
I downloaded Vue.js DevTools but it doesn't work in the app. A message is displayed that Vue.js was not found on the page.

Answer 1

Usually all errors are visible in the browser developer console.
Press F12 and see what's wrong.

Answer 2

There was the same problem, turning off any adblocks helped vue immediately earned.