Getting "cm is not a function" in NextJs

Hi,
I am getting the below error in NextJs. I have tried downgrading the version but it is not getting resolved. Please help!

The versions I have tried -
v7.2.1 (latest)
v7.1.0
v7.0.0
v6.0.1

Unhandled Runtime Error
TypeError: cm is not a function

Call Stack
Controlled.componentDidMount
node_modules\react-codemirror2\index.js (498:0)
commitLayoutEffectOnFiber
node_modules\react-dom\cjs\react-dom.development.js (23305:0)
commitLayoutMountEffects_complete
node_modules\react-dom\cjs\react-dom.development.js (24688:0)
commitLayoutEffects_begin
node_modules\react-dom\cjs\react-dom.development.js (24674:0)
commitLayoutEffects
node_modules\react-dom\cjs\react-dom.development.js (24612:0)

I have the same problem.

Uncaught TypeError: cm is not a function

I encountered this problem on react18. When react17 was executed, no error was reported, is also nextjs.

i saw this on error page

var React = require('react');

var SERVER_RENDERED = typeof navigator === 'undefined' || global['PREVENT_CODEMIRROR_RENDER'] === true;
var cm;

if (!SERVER_RENDERED) {
  cm = require('codemirror');
}

solution - get codemirror@5

I had same problem:
"react-codemirror2": "^8.0.0",
"react": "^18.2.0",
"codemirror": "^6.0.1",

Error goes away when i uninstall install codemirror and install codemirror@5 -- which gets me to
"codemirror": "^5.65.16"

@filip-savic-bm

@filip-savic-bm thanks, it helps me!

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Getting "cm is not a function" in NextJs #298

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bursonyang commented on Mar 14, 2023

shmjiao commented on Mar 31, 2023

ruanjiayou commented on Apr 13, 2023

filip-savic-bm commented on Apr 22, 2024

yunseop-dev commented on Apr 29, 2025

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