Promise In Next Config
Why This Error Occurred​
The webpack function in next.config.js returned a promise which is not supported in Next.js. For example, below is not supported:
module.exports = {
webpack: async function (config) {
return config
},
}
Possible Ways to Fix It​
In Next.js versions above 12.0.10, module.exports = async () => is supported.
For older versions, you can check your next.config.js for async or return Promise.
Potentially a plugin is returning a Promise from the webpack function.