Trying to convert PDF to PNG

[MatthD]

Configuration:
MACOS Hsierra, Node 8.7.0

What is the expected behavior?

I am just trying to convert a pdf to png like in the example but with a chain treatment.

What went wrong?

It's says windows is not defined & speaks about a binding thing that should be in the main thread ..

# PDF document loaded.
# PDF document loaded.
# PDF document loaded.
Error: bind() shall be called from main thread
    at error (src/worker/ocr/node_modules/pdfjs-dist/build/pdf.js:291:17)
    at assert (src/worker/ocr/node_modules/pdfjs-dist/build/pdf.js:306:5)
    at FontLoader.fontLoaderBind [as bind] (src/worker/ocr/node_modules/pdfjs-dist/build/pdf.js:2707:5)
    at WorkerTransport.transportObj (src/worker/ocr/node_modules/pdfjs-dist/build/pdf.js:10140:29)
    at MessageHandler.messageHandlerComObjOnMessage (src/worker/ocr/node_modules/pdfjs-dist/build/pdf.js:1605:19)
    at Object.<anonymous> (src/worker/ocr/node_modules/pdfjs-dist/build/pdf.js:9889:24)
    at Array.forEach (<anonymous>)
    at Object.postMessage (src/worker/ocr/node_modules/pdfjs-dist/build/pdf.js:9888:29)
    at MessageHandler.postMessage (src/worker/ocr/node_modules/pdfjs-dist/build/pdf.worker.js:3695:19)
    at MessageHandler.messageHandlerSend [as send] (src/worker/ocr/node_modules/pdfjs-dist/build/pdf.worker.js:3656:10)
    at TranslatedFont.send (src/worker/ocr/node_modules/pdfjs-dist/build/pdf.worker.js:39057:15)
    at src/worker/ocr/node_modules/pdfjs-dist/build/pdf.worker.js:37236:20
    at <anonymous>
(node:18858) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): ReferenceError: window is not defined
(node:18858) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
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