[webpack.cache.PackFileCacheStrategy] Caching failed for pack: TypeError: Cannot read properties of undefined (reading ‘length’)

We develop apps in Next.js and Node.js.
During the development phase, I get this error on the client side.
Is there a solution?

** [webpack.cache.PackFileCacheStrategy] Caching failed for pack: TypeError: Cannot read properties of undefined (reading ‘length’)
**

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I think I got this error around the time I touched the JSX CSS, but I don’t actually know if it’s related because this error appears even after removing JSX.

I am not using the length variable from where I worked again. So why does it say this is unreadable?
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I have commented out or deleted the area I worked on, but nothing has changed. I have a feeling it is something else.