Webpack watch not working on Webstorm on Windows?

Seems Webpack watch doesn't work if the file is not saved directly. Please try turning 'Safe write' option ( Settings | Appearance & Behavior | System Settings | Use "safe write" (save changes to temporary file first)) off.

In 2020.* the option name is Back up files before saving

Also make sure you use Node's path construction instead of slashes. Example:

entry: {
     'MyPackage': path.join(__dirname, 'modules', 'PkgEntry.js'),
...

instead of:

entry: {
     'MyPackage': '\\modules\\PkgEntry.js'),
...