array-flatten

[ranouf]

Hi,

I deployed my next.js webapp in azure web app and I have an issue in the log when I open the url:

Cannot find module 'array-flatten'Require stack:- C:\home\site\wwwroot\node_modules\express\lib\router\route.js- C:\home\site\wwwroot\node_modules\express\lib\router\index.js- C:\home\site\wwwroot\node_modules\express\lib\application.js- C:\home\site\wwwroot\node_modules\express\lib\express.js- C:\home\site\wwwroot\node_modules\express\index.js- C:\home\site\wwwroot\server.js- C:\Program Files (x86)\iisnode\interceptor.jsat Module._resolveFilename (node:internal/modules/cjs/loader:1225:15)at Module._load (node:internal/modules/cjs/loader:1051:27)at Module.require (node:internal/modules/cjs/loader:1311:19)at Module.patchedRequire (C:\PROGRA2\SITEEX1\NODEAP1\2111.4\nodejs\node_modules\diagnostic-channel\dist\src\patchRequire.js:16:46)at Hook._require.Module.require (C:\PROGRA2\SITEEX1\NODEAP1\2111.4\nodejs\node_modules\require-in-the-middle\index.js:167:34)at require (node:internal/modules/helpers:179:18)at Object. (C:\home\site\wwwroot\node_modules\express\lib\router\route.js:17:15)at Module._compile (node:internal/modules/cjs/loader:1469:14)at Module._extensions..js (node:internal/modules/cjs/loader:1548:10)at Module.load (node:internal/modules/cjs/loader:1288:32)Application has thrown an uncaught exception and is terminated:Error: Cannot find module 'array-flatten'Require stack:- C:\home\site\wwwroot\node_modules\express\lib\router\route.js- C:\home\site\wwwroot\node_modules\express\lib\router\index.js- C:\home\site\wwwroot\node_modules\express\lib\application.js- C:\home\site\wwwroot\node_modules\express\lib\express.js- C:\home\site\wwwroot\node_modules\express\index.js- C:\home\site\wwwroot\server.js- C:\Program Files (x86)\iisnode\interceptor.jsat Module._resolveFilename (node:internal/modules/cjs/loader:1225:15)at Module._load (node:internal/modules/cjs/loader:1051:27)at Module.require (node:internal/modules/cjs/loader:1311:19)at Module.patchedRequire (C:\PROGRA2\SITEEX1\NODEAP1\2111.4\nodejs\node_modules\diagnostic-channel\dist\src\patchRequire.js:16:46)at Hook._require.Module.require (C:\PROGRA2\SITEEX1\NODEAP1\2111.4\nodejs\node_modules\require-in-the-middle\index.js:167:34)at require (node:internal/modules/helpers:179:18)at Object. (C:\home\site\wwwroot\node_modules\express\lib\router\route.js:17:15)at Module._compile (node:internal/modules/cjs/loader:1469:14)at Module._extensions..js (node:internal/modules/cjs/loader:1548:10)at Module.load (node:internal/modules/cjs/loader:1288:32)

When I look in package.json, I added the package array-flatten just in case, but still continue to get the issue:

"dependencies": {
    "@emotion/react": "11.14.0",
    "@emotion/styled": "11.14.0",
    "@mui/x-data-grid": "8.2.0",
    "@next/eslint-plugin-next": "14.0.4",
    "array-flatten": "^3.0.0",
    "bcrypt": "5.1.1",
    "bootstrap": "5.3.5",
    "express": "5.1.0",
    "firebase": "11.6.1",
    "leaflet": "1.9.4",
    "leaflet-defaulticon-compatibility": "0.1.2",
    "mongoose": "8.14.1",
    "next": "15.3.1",
    "next-auth": "4.24.11",
    "react": "18.3.1",
    "react-autosuggest": "10.1.0",
    "react-bootstrap": "2.10.9",
    "react-dom": "18.3.1",
    "react-firebase-hooks": "5.1.1",
    "react-icons": "4.12.0",
    "react-leaflet": "4.2.1",
    "react-toastify": "10.0.4",
    "react-tooltip": "4.5.1",
    "recharts": "2.15.3",
    "webpack": "5.99.7",
    "webpack-cli": "6.0.1"
  },
  "devDependencies": {
    "@types/node": "22.15.3",
    "eslint": "9.25.1",
    "eslint-config-next": "15.3.1"
  }

Any idea how to fix it?

[krzysdz]

router since version 2.1.0 does not use array-flatten (see pillarjs/router#126). Express 5.1.0, which you have listed in package.json depends on router@^2.2.0.

Did you try removing node_modules and package-lock.json and running npm install again? The require stack points to express/lib/router/route.js, which was there in Express 4, but does not exist in Express 5 - it has been separated into router package).