I completly reinstalled node_modules like 5 times already but I still keep getting a ton of these errors. The paths it shows me in the error message as sources are a ton of /node_modules/next/dist/... but how am I supposed to fix those if reinstalling doesn't help???

Can you provide a screenshot of your file structure?

Sure

It also happens with fresh projects I create (at least in the parent folder, haven't tried in another one. Will check now)

Works in other folders.
Did it like this

nextjs-projects
â”” My issue project
  â”” client         // doesn't work
  â”” server
â”” My test project  // works

Have you tried deleting .next folder?

I didn't do that. Does it recreate itself again when I run npm run dev?

Yep

It’s basically cache files

Oh, right

I just delted both node_modules and .next but I get the same errors again

Strange, try renaming “client” folder to something else?

Nope, no luck.
Here's a full error btw:

./node_modules/next/dist/shared/lib/router/utils/is-bot.js
There are multiple modules with names that only differ in casing.
This can lead to unexpected behavior when compiling on a filesystem with other case-semantic.
Use equal casing. Compare these module identifiers:
* javascript/auto|C:\Users\Niclas\Desktop\nextjs\reved-ddf\something-else\node_modules\next\dist\compiled\@next\react-refresh-utils\dist\loader.js!C:\Users\Niclas\Desktop\nextjs\reved-ddf\something-else\node_modules\next\dist\build\webpack\loaders\next-flight-client-module-loader.js!C:\Users\Niclas\Desktop\nextjs\reved-ddf\something-else\node_modules\next\dist\build\webpack\loaders\next-swc-loader.js??ruleSet[1].rules[7].oneOf[4].use[2]!C:\Users\Niclas\Desktop\nextjs\reved-ddf\something-else\node_modules\next\dist\shared\lib\router\utils\is-bot.js|app-pages-browser
    Used by 1 module(s), i. e.
    javascript/auto|C:\Users\Niclas\Desktop\nextjs\reved-ddf\something-else\node_modules\next\dist\compiled\@next\react-refresh-utils\dist\loader.js!C:\Users\Niclas\Desktop\nextjs\reved-ddf\something-else\node_modules\next\dist\build\webpack\loaders\next-flight-client-module-loader.js!C:\Users\Niclas\Desktop\nextjs\reved-ddf\something-else\node_modules\next\dist\build\webpack\loaders\next-swc-loader.js??ruleSet[1].rules[7].oneOf[4].use[2]!C:\Users\Niclas\Desktop\nextjs\reved-ddf\something-else\node_modules\next\dist\client\components\app-router.js|app-pages-browser
* javascript/auto|C:\Users\Niclas\Desktop\nextjs\reved-ddf\something-else\node_modules\next\dist\compiled\@next\react-refresh-utils\dist\loader.js!C:\Users\Niclas\Desktop\nextjs\reved-ddf\something-else\node_modules\next\dist\build\webpack\loaders\next-flight-client-module-loader.js!C:\Users\Niclas\Desktop\nextjs\reved-ddf\something-else\node_modules\next\dist\build\webpack\loaders\next-swc-loader.js??ruleSet[1].rules[7].oneOf[4].use[2]!C:\Users\Niclas\desktop\nextjs\reved-ddf\something-else\node_modules\next\dist\shared\lib\router\utils\is-bot.js|app-pages-browser
    Used by 1 module(s), i. e.
    javascript/auto|C:\Users\Niclas\Desktop\nextjs\reved-ddf\something-else\node_modules\next\dist\compiled\@next\react-refresh-utils\dist\loader.js!C:\Users\Niclas\Desktop\nextjs\reved-ddf\something-else\node_modules\next\dist\build\webpack\loaders\next-flight-client-module-loader.js!C:\Users\Niclas\Desktop\nextjs\reved-ddf\something-else\node_modules\next\dist\build\webpack\loaders\next-swc-loader.js??ruleSet[1].rules[7].oneOf[4].use[2]!C:\Users\Niclas\desktop\nextjs\reved-ddf\something-else\node_modules\next\dist\client\components\app-router.js|app-pages-browser

Import trace for requested module:
./node_modules/next/dist/shared/lib/router/utils/is-bot.js
./node_modules/next/dist/client/components/app-router.js

It's basically this getting spammed into my console for various modules from Next.js

I also just created a whole new project so like that:

nextjs-projects
â”” My issue project
  â”” client         // doesn't work
  â”” server
â”” My test project  // works
â”” New project
  â”” client         // doesn't work

I don't know why it is but it is only when I use those subfolders

I don't get why it cares about where the project is located

Ok, now also other projects don't work anymore WTF