NullReferenceException when minimizing signalr.js

[IndigoHealth]

BundlerMinifier refuses to minimize the Microsoft signalr.js (version 6.0.7) distribution file.

My libman.json (edited to remove all other package references):

{
  "version": "1.0",
  "defaultProvider": "cdnjs",
  "libraries": [
    {
      "library": "[email protected]",
      "destination": "wwwroot/lib/microsoft-signalr/"
    }
  ]
}

My bundleconfig.json (edited to remove all other package references):

[
  {
    "outputFileName": "wwwroot/bundles/signalr.js",
    "inputFiles": [
      "wwwroot/lib/microsoft-signalr/signalr.js"
    ]
  }
]

Sometimes (but not always) BundlerMinifier displays an error in the output log complaining that it can't minimize signalr.js. The Error List almost always displays this error:

Installed product versions

• Visual Studio Professional 2022 (64-bit) Version 17.2.6
• Bundler & Minifier - 2.9.3