CSS Error: Unexpected Token

[xxxLukskyxxx]

• Version:
  22.11.7

• Target:
  Windows 10 x64

When i start webpack-electron some errors with css files occur. If I start the webpack-dev-server it works well.... Does somebody have an idea to fix that ?
Thanke you :)

ERROR in ./src/modules/live-preview/live-preview.css 1:0
    Module parse failed: Unexpected token (1:0)
    You may need an appropriate loader to handle this file type, currently no loaders are configured to process this file. See https://webpack.js.org/concepts#loaders
    > .live-preview {
    |   position: sticky;
    |   top: 20%;
     @ ./src/modules/live-preview/index.ts 2:0-28
     @ ./src/app.tsx
     @ ./src/index.tsx
     @ multi ./src/index.tsx

    ERROR in ./src/styles.css 1:11
    Module parse failed: Unexpected token (1:11)
    You may need an appropriate loader to handle this file type, currently no loaders are configured to process this file. See https://webpack.js.org/concepts#loaders
    > html, body {
    |     height: 100%;
    | }
     @ ./src/index.tsx 7:0-22
     @ multi ./src/index.tsx

    ERROR in ./node_modules/json-path-picker/lib/json-path-picker.css 2:28
    Module parse failed: Unexpected token (2:28)
    You may need an appropriate loader to handle this file type, currently no loaders are configured to process this file. See https://webpack.js.org/concepts#loaders
    | /* Syntax highlighting for JSON objects */
    > ul.json-dict, ol.json-array {
    |   list-style-type: none;
    |   margin: 0 0 0 1px;
     @ ./src/index.tsx 6:0-51
     @ multi ./src/index.tsx
    ERROR in ./node_modules/bootstrap/dist/css/bootstrap.css 7:0
    Module parse failed: Unexpected token (7:0)
    You may need an appropriate loader to handle this file type, currently no loaders are configured to process this file. See https://webpack.js.org/concepts#loaders
    |  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
    |  */
    > :root {
    |   --blue: #007bff;
    |   --indigo: #6610f2;
     @ ./src/index.tsx 4:0-42
     @ multi ./src/index.tsx

This is my Webpack config

  "version": "1.0.0",
  "main": "index.js",
  "scripts": {
    "build": "webpack --mode=production",
    "compile": "electron-webpack",
    "start": "webpack-dev-server",
    "test": "echo \"Error: no test specified\" && exit 1",
    "lint": "tslint -p tsconfig.json"
  },
  "electronWebpack": {
    "main": {
      "sourceDirectory": "src"
    },
    "renderer": {
      "sourceDirectory": "src"
    }
  },
  "devDependencies": {
    "@babel/preset-react": "^7.14.5",
    "@types/jquery": "^3.5.0",
    "@types/lodash": "^4.14.157",
    "@types/react": "^16.9.43",
    "@types/react-dom": "^16.9.8",
    "@types/webpack-env": "^1.15.2",
    "css-loader": "^5.2.7",
    "electron": "^13.2.2",
    "electron-builder": "^22.11.7",
    "electron-webpack": "^2.8.2",
    "electron-webpack-ts": "^4.0.1",
    "file-loader": "^6.0.0",
    "html-loader": "^1.1.0",
    "html-webpack-plugin": "^4.3.0",
    "node-sass": "^6.0.1",
    "sass-loader": "^12.1.0",
    "source-map-loader": "^1.0.1",
    "style-loader": "^1.2.1",
    "ts-loader": "^8.3.0",
    "tslint": "^6.1.2",
    "typescript": "^3.9.6",
    "webpack": "^4.46.0",
    "webpack-cli": "^3.3.12",
    "webpack-dev-server": "^3.11.2"
  },
  "dependencies": {
    "@json-editor/json-editor": "^2.5.4",
    "bootstrap": "^4.5.0",
    "file-saver": "^2.0.2",
    "jimp": "^0.14.0",
    "jquery": "^3.5.1",
    "json-path-picker": "^0.2.0",
    "jszip": "^3.7.0",
    "lodash": "^4.17.21",
    "popper.js": "^1.16.1",
    "react": "^16.13.1",
    "react-dom": "^16.13.1",
    "split.js": "^1.6.2"
  }
}