TypeError: Cannot read property 'forEach' of undefined

Issue description

When running the CLI on a stats file (not all stats files, just some), I'm getting the following error, and the following error only:

Could't analyze webpack bundle:
TypeError: Cannot read property 'forEach' of undefined

It's not a lot to go on, there aren't any helpful hints or file names in which it crashes.

Technical info

System:
    OS: macOS 11.6
    CPU: (12) x64 Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
    Memory: 3.08 GB / 16.00 GB
    Shell: 5.8 - /bin/zsh
  Binaries:
    Node: 12.22.0 - ~/.nvm/versions/node/v12.22.0/bin/node
    Yarn: 1.22.17 - ~/.nvm/versions/node/v12.22.0/bin/yarn
    npm: 6.14.15 - ~/.nvm/versions/node/v12.22.0/bin/npm
  npmPackages:
    terser-webpack-plugin: 5.1.3 => 5.1.3 
    webpack: 5.64.1 => 5.64.1 
    webpack-cli: 4.7.2 => 4.7.2 
    webpack-dev-server: 4.7.3 => 4.7.3 
    webpack-manifest-plugin: 3.1.1 => 3.1.1 

Debug info

Using the CLI - npx webpack-bundle-analyzer@latest stats.json, with the following plugins:

• @sentry/webpack-plugin
• terser-webpack-plugin
• webpack-manifest-plugin
• mini-css-extract-plugin
• terser-webpack-plugin
• webpack.ContextReplacementPlugin
• webpack.DefinePlugin

Start by reproducing the CLI invocation npx webpack-bundle-analyzer@latest stats.json with a stats file that triggers the error, using the listed webpack plugins as context. Trace the CLI's stats-file analysis until the undefined value is identified, then make the failure report actionable and verify that affected stats files no longer produce the unhelpful TypeError.