Почему возникает ошибка You have tried to call .then(), .catch()?

Обновление-2

Поиск .then(), .catch() await

Обновление-2
\db\connection.js

const mysql = require('mysql2');
const config = require('../config.json');
const connection = mysql.createConnection({
  host: config.mysql.host,
  user: config.mysql.user,
  password: config.mysql.password,
  database: config.mysql.db,
  charset: 'utf8_general_ci',
  multipleStatements: true
});

connection.connect();

module.exports = connection;

Картинка. Поиск "mysql2"

Почему возникает ошибка You have tried to call .then(), .catch()?

Картинка: поиск .then(), .catch() await

Почему возникает ошибка You have tried to call .then(), .catch()?

…\controllers\main.js

const db = require('../db');
const fs = require('fs');
const path = require('path');
const config = require('../config.js');
class Main {

  async video(req, res, next) {
    const videoFolder = './static/video'
    let videos = []

    fs.readdirSync(videoFolder).forEach((file) => {
      let extension = path.extname(file)
      let filename = path.basename(file, extension)

      videos.push({
        file,
        filename: parseInt(filename),
      })
    })

    videos = videos.sort((a, b) => {
      return a.filename - b.filename
    })



    return res.render('video', {
      domain: config.express.domain,
      videos,
    })
  }

    async panomuseum(req, res) {
    const article = await db.article.getByID(req.params.lang);
    const sub = await db.article.getRoot(req.params.lang);
    const files = await db.files.getByOwnerId(req.params.lang);

    const lang = await db.lang.getById(req.params.lang);

    return res.render('panomuseum', {
      article,
      sub,
      files,
      lang
    });
  }

  async panomuseum2(req, res) {
    const article = await db.article.getByID(req.params.lang);
    const sub = await db.article.getRoot(req.params.lang);
    const files = await db.files.getByOwnerId(req.params.lang);

    const lang = await db.lang.getById(req.params.lang);

    return res.render('panomuseum2', {
      article,
      sub,
      files,
      lang
    });
  }

  async panotheatre(req, res) {
    const article = await db.article.getByID(req.params.lang);
    const sub = await db.article.getRoot(req.params.lang);
    const files = await db.files.getByOwnerId(req.params.lang);

    const lang = await db.lang.getById(req.params.lang);

    return res.render('panotheatre', {
      article,
      sub,
      files,
      lang
    });
  }

  async index(req, res) {
    const article = await db.article.getByID(req.params.lang);
    const sub = await db.article.getRoot(req.params.lang);
    const files = await db.files.getByOwnerId(req.params.lang);


    const lang = await db.lang.getById(req.params.lang);
    const timeout = await db.settings.getByID("timeout");
    const caption = await db.settings.getByID("caption");


    return res.render("index", {
      article,
      sub,
      files,
      lang,
      timeout,
      caption,
      domain: req.app.get("domain"),
    });
  }

  async menu(req, res) {
    return res.render("menu", {
      domain: req.app.get("domain"),
    });
  }

  async slideshow(req, res) {
    const slideshow = await db.files.getSlideshow();
    const timer = await db.settings.getByID("timer");

    return res.render("slideshow", {
      slideshow,
      timer,
      domain: req.app.get("domain"),
    });
  }

  async slide(req, res) {
    const slideshow = await db.files.getByID(req.params.id);
    const timer = await db.settings.getByID("timer");

    return res.render("slideshow", {
      slideshow: [slideshow],
      timer,
      domain: req.app.get("domain"),
    });
  }

  async article(req, res) {
    const article = await db.article.getByID(req.params.id);
    const sub = await db.article.getSub(req.params.id);
    const files = await db.files.getByOwnerId(req.params.id);
    const id = req.params.id;
    const lang = await db.lang.getById(req.params.lang);
    const timeout = await db.settings.getByID("timeout");
    const caption = await db.settings.getByID("caption");

    return res.render("index", {
      id,
      article,
      sub,
      files,
      lang,
      timeout,
      caption,
      domain: req.app.get("domain"),
    });
  }

  
  async lang(req, res) {
    const langs = await db.lang.getAll();

    let activeCount = 0;

    for (let lang of langs) {
      if (lang.value == 1) {
        activeCount++;
      }
    }

    if (activeCount == 0) {
      return res.redirect("/0");
    } else if (activeCount == 1) {
      for (let lang of langs) {
        if (lang.value == 1) {
          return res.redirect("/" + lang.id);
        }
      }
    }

    const timeout = await db.settings.getByID("timeout");

    return res.render("lang", {
      langs,
      timeout,
    });
  }

  async openSlide(req, res) {
    console.log("openSlide");
    let files = await db.files.getSyncSmartHome();

    parentIO.sockets.in("client").emit("goToUrl", {
      message: "/slide/" + files[parseInt(req.params.id)].id,
    });

    return res.json({
      success: true,
    });
  }

  async openSlideshow(req, res) {
    console.log("open slideshow");

    parentIO.sockets.in("client").emit("goToUrl", {
      message: "/slideshow",
    });

    return res.json({
      success: true,
    });
  }
}

module.exports = new Main();

Почему возникает ошибка You have tried to call .then(), .catch()?

Какой код выложить?
Это?
at Query.then (e:\Test\Pro01\node_modules\mysql2\lib\commands\query.js:41:11)
at MySQLStore.query (e:\Test\Pro01\node_modules\express-mysql-session\index.js:392:12)
at MySQLStore. (e:\Test\Pro01\node_modules\express-mysql-session\index.js:110:9)
at FSReqCallback.readFileAfterClose [as oncomplete] (node:internal/fs/read_file_context:68:3)

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Я только разбираюсь с NODE JS.
Прошу извинить за некорректность...

Обновление-1
Эли это замечание по всему проекту?

Обновление-2
См. вопрос Обновление-1
Добавил код app.js