Could not load the configuration file: v is not a function

[DopamineDriven]

I've followed the steps for using the pnpx @tailwindcss/upgrade@next command and it keeps coming back to the same ambiguous error

Could not load the configuration file: v is not a function

here are my recent bash logs

dopaminedriven@LAPTOP-2IH011V4:~/personal/portfolio-2025/apps/chess-v2$ nvm use 20.18.0
Now using node v20.18.0 (npm v10.9.0)
dopaminedriven@LAPTOP-2IH011V4:~/personal/portfolio-2025/apps/chess-v2$ pnpx @tailwindcss/upgrade@next --force
≈ tailwindcss v4.0.0

│ Searching for CSS files in the current directory and its subdirectories… 

│ ↳ Linked `./tailwind.config.ts` to `./src/app/globals.css` 

│ Migrating JavaScript configuration files… 

│ ↳ Could not load the configuration file: v is not a function 

dopaminedriven@LAPTOP-2IH011V4:~/personal/portfolio-2025/apps/chess-v2$ pnpx @tailwindcss/upgrade@next --force
≈ tailwindcss v4.0.0

│ Searching for CSS files in the current directory and its subdirectories… 

│ ↳ Linked `./tailwind.config.ts` to `./src/app/globals.css` 

│ Migrating JavaScript configuration files… 

│ ↳ Could not load the configuration file: v is not a function 

dopaminedriven@LAPTOP-2IH011V4:~/personal/portfolio-2025/apps/chess-v2$ nvm use --lts
Now using node v22.13.1 (npm v11.0.0)
dopaminedriven@LAPTOP-2IH011V4:~/personal/portfolio-2025/apps/chess-v2$ cd ../..
dopaminedriven@LAPTOP-2IH011V4:~/personal/portfolio-2025$ pnpx @tailwindcss/upgrade@next --config apps/chess-v2/tailwind.config.ts --force
≈ tailwindcss v4.0.0

│ Searching for CSS files in the current directory and its subdirectories… 

│ ↳ Could not determine configuration file for: `./apps/chess/src/app/globals.css` 
│   Update your stylesheet to use `@config` to specify the correct configuration file explicitly and then run the upgrade tool again. 

│ ↳ Could not determine configuration file for: `./apps/chess-v2/src/app/globals.css` 
│   Update your stylesheet to use `@config` to specify the correct configuration file explicitly and then run the upgrade tool again. 

│ ↳ Could not determine configuration file for: `./apps/web/src/app/global.css` 
│   Update your stylesheet to use `@config` to specify the correct configuration file explicitly and then run the upgrade tool again. 

so at this point I followed the instructions to update my apps/{chess,chess-v2,web}/src/app/global(s).css files in each of the three repos within the apps directory (pnpm workspace using turborepo). The first several lines in each of the three root app directory css files all look identical and have identical relative paths to each of their respective configs

@config "../../tailwind.config.ts";
@tailwind base;
@tailwind components;
@tailwind utilities;

after making these updates, I tried again

dopaminedriven@LAPTOP-2IH011V4:~/personal/portfolio-2025$ pnpx @tailwindcss/upgrade@next --force
≈ tailwindcss v4.0.0

│ Searching for CSS files in the current directory and its subdirectories… 

│ Migrating JavaScript configuration files… 

│ ↳ Could not load the configuration file: v is not a function 

dopaminedriven@LAPTOP-2IH011V4:~/personal/portfolio-2025$ pnpx @tailwindcss/upgrade@next --config apps/chess-v2/tailwind.config.ts --force
≈ tailwindcss v4.0.0

│ Searching for CSS files in the current directory and its subdirectories… 

│ Migrating JavaScript configuration files… 

│ ↳ Could not load the configuration file: v is not a function 

I decided to look into the source code (specifically the bin file) in the @tailwindcss/upgrade package (src/index.ts).

however the only configured cli flag options I could find in the file are the following

const options = {
  '--config': { type: 'string', description: 'Path to the configuration file', alias: '-c' },
  '--help': { type: 'boolean', description: 'Display usage information', alias: '-h' },
  '--force': { type: 'boolean', description: 'Force the migration', alias: '-f' },
  '--version': { type: 'boolean', description: 'Display the version number', alias: '-v' },
} satisfies Arg

Any tips on what I could be doing wrong (or not doing right) for these errors to keep occurring?

note: I am using shiki v2+ in the apps/web repo as it handles mdx, syntax highlighting etc

I got the following warning from pnpm when trying to install the @tailwindcss/upgrade package as a dev dependency in each of the three repos within apps directory of the monorepo (to see if it might work that way)

 WARN  Issues with peer dependencies found
.
└─┬ @tailwindcss/upgrade 4.0.0
  └─┬ tree-sitter-typescript 0.23.2
    ├── ✕ unmet peer tree-sitter@^0.21.0: found 0.22.4
    └─┬ tree-sitter-javascript 0.23.1
      └── ✕ unmet peer tree-sitter@^0.21.1: found 0.22.4

so I'm a bit lost as to how to proceed

specs

using node v22.13.1 (npm v11.0.0)

tried using v20.18.0 to no avail hoping that might do the trick

repo is public facing -- find it here

feedback/advice would be greatly appreciated 🙏

[wongjn]

It would seem like the Tailwind plugins you use, at least tailwindcss-animate or tailwindcss-motion or both may be causing the error.

[wongjn]

You could remove them, run the migration, and then add them back in manually via @plugin.

[trvhung]

You could remove them, run the migration, and then add them back in manually via @plugin.

remove all plugin and update but still error

[wongjn]

What's the error you are receiving?

[DopamineDriven]

got it working, thanks for the suggestion

just an fyi for anyone else who is using the next Image placeholder="blur" field in their code, the migration will change the value of this field from the valid "blur" to "blur-sm" (valid options include only "blur" | "empty")

make sure to check for that before deploying because I sure didn't notice until a build error

[VickyAgravat]

Yes, tailwindcss-animate cause error.
I have removed from tailwind.config.js and it works.

[MADEiN83]

Hi,
I had the same issue and agree, it's due to TW plugins. In my case, it was due to fluid-tailwind plugin.

[trvhung]

same problem, can i help us

[ksb2311]

Go to folder where your css is.
I was running command in project root folder which gave me mentioned error.
So i entered in a folder where my style.css (/public/style.css) is and then run a command there and it worked.

[NormandoHall]

Same. Removing tailwindcss-forms fixes

[vinnymac]

It would be nice if instead of throwing these errors if the upgrade tool would recommend removing plugins and adding them back manually (or prompting the user and doing it itself, ya know to handle the upgrade?)