Invalid options object when running `electron-forge start`

Preflight Checklist

• I have read the contribution documentation for this project.
• I agree to follow the code of conduct that this project follows, as appropriate.
• I have searched the issue tracker for a bug that matches the one I want to file, without success.

Issue Details

• Electron Forge Version:
  • 6.0.0-beta.55
• Electron Version:
  • 11.4.1
• Operating System:
  • Windows 10
• Last Known Working Electron Forge version::
  • 6.0.0-beta.54

Expected Behavior

Running the Electron app in dev mode should work.

Actual Behavior

When running electron-forge start it prints the following output:

√ Checking your system
√ Locating Application
√ Preparing native dependencies: 1 / 1
√ Compiling Main Process Code
× Launch Dev Servers

An unhandled error has occurred inside Forge:
Invalid options object. Dev Middleware has been initialized using an options object that does not match the API schema.
 - options has an unknown property 'historyApiFallback'. These properties are valid:
   object { mimeTypes?, writeToDisk?, methods?, headers?, publicPath?, stats?, serverSideRender?, outputFileSystem?, index? }
ValidationError: Invalid options object. Dev Middleware has been initialized using an options object that does not match the API schema.
 - options has an unknown property 'historyApiFallback'. These properties are valid:
   object { mimeTypes?, writeToDisk?, methods?, headers?, publicPath?, stats?, serverSideRender?, outputFileSystem?, index? }
    at validate (<project-path>\electron\node_modules\webpack-dev-middleware\node_modules\schema-utils\dist\validate.js:104:11)
    at wdm (<project-path>\electron\node_modules\webpack-dev-middleware\dist\index.js:29:29)
    at <project-path>\electron\node_modules\@electron-forge\plugin-webpack\src\WebpackPlugin.ts:292:22
    at processTicksAndRejections (internal/process/task_queues.js:93:5)

I updated electron-forge from 6.0.0-beta.54 to 6.0.0-beta.55 and did not change any configuration.

To Reproduce

Additional Information

[Xananax]

Edit the generated package.json and change the version of

"@electron-forge/plugin-webpack": "6.0.0-beta.54",

to .54 instead of .55.

I believe the faulty change is here: https://github.com/electron-userland/electron-forge/commit/790647dc7314eac40735f8d67ba831a8991d4bd4

[jhofer]

I have the same issue when creating a new app using the webpack-typescript template: https://www.electronforge.io/templates/typescript-+-webpack-template