Webpack: "there are multiple modules with names that only differ in casing" but modules referenced are identical

This is usually a result of a minuscule typo.

For instance, if you are importing your modules like import Vue from 'vue', import Vuex from 'vuex'.

Go through your files and check where you used from 'Vue' or from 'Vuex' - make sure to use the exact same capitals (uppercase letters) as in your import statements.

The error descriptions should have been written more clearly, but what I explained has been the cause of my problem each time for this error on webpack commands.

For others that are facing this issue and tried the suggested fixes with no luck, here is another possible solution.

Ensure that the path you used in your terminal has the correct capitalization. For example if you're using git bash on Windows and your project has the following path:

C:\MyProjects\project-X

If you access it using cd /c/myprojects/project-x (note the lack of capital cases) and then run npm start you might face this problem.

The solution would be to consider the project path case-sensitive and use it as follows:

cd /C/MyProjects/project-X

It happened to me on angular 6. It's capital and small letter misusage error which your ide or text editor may ignore. I USED

import { PayComponent }      from './payment/pay/pay.component';

INSTEAD OF

import { PayComponent }      from './Payment/pay/pay.component';

IMAGINE JUST "P" and "p". Goodluck.