@blocknote/mantine v0.40.0 incompatible with Mantine v8 with CSS import errors

[kkartch]

Describe the bug
BlockNote v0.40.0 mentions that support was added for Mantine v8, but the build fails in a minimal Vite project due to incorrect CSS imports in @blocknote/mantine/src/mantineStyles.css.

Error:

Unable to resolve `@import "@mantine/core/styles/ScrollArea.css"` from /private/tmp/blocknote-mantine-test/node_modules/@blocknote/mantine/src
✓ 459 modules transformed.
✗ Build failed in 701ms
error during build:
[vite:css] [postcss] ENOENT: no such file or directory, open '@mantine/core/styles/ScrollArea.css'
file: /private/tmp/blocknote-mantine-test/node_modules/@blocknote/mantine/src/style.css:undefined:NaN
    at async open (node:internal/fs/promises:638:25)
    at async Object.readFile (node:internal/fs/promises:1238:14)
    at async Object.load (file:///private/tmp/blocknote-mantine-test/node_modules/vite/dist/node/chunks/dep-Bu492Fnd.js:43745:25)
    at async loadImportContent (file:///private/tmp/blocknote-mantine-test/node_modules/vite/dist/node/chunks/dep-D67CHC8_.js:673:19)
    at async Promise.all (index 0)
    at async resolveImportId (file:///private/tmp/blocknote-mantine-test/node_modules/vite/dist/node/chunks/dep-D67CHC8_.js:629:27)
    at async parseStyles$1 (file:///private/tmp/blocknote-mantine-test/node_modules/vite/dist/node/chunks/dep-D67CHC8_.js:537:5)
    at async Promise.all (index 0)
    at async resolveImportId (file:///private/tmp/blocknote-mantine-test/node_modules/vite/dist/node/chunks/dep-D67CHC8_.js:629:27)
    at async parseStyles$1 (file:///private/tmp/blocknote-mantine-test/node_modules/vite/dist/node/chunks/dep-D67CHC8_.js:537:5)

To Reproduce
I created a minimal Vite + React project and was able to reproduce the error with only packages added for BlockNote.

• BlockNote v0.40.0 + Mantine v8.3.3 - Build fails
• BlockNote v0.39.1 + Mantine v7.17.8 - Build succeeds

The example project is available here: https://github.com/kkartch/blocknote-mantine-v8-repro

Misc

• Node version: v22.8.0
• Package manager: pnpm v10.2.0
• Browser:
• I'm a sponsor and would appreciate if you could look into this sooner than later 💖

[Paarth-K]

Facing the same issue on Next.js 15.5.4

[sami-t]

Try replacing import "@blocknote/mantine/style.css" with import "@blocknote/mantine/blocknoteStyles.css"

[nperez0111]

I believe this issue is related to: #2062

So, I think downgrading mantine might be the best answer at the moment