Unable to Switch to reader view: Readability.js:1019 Uncaught TypeError

[jefferyyuan]

• Sometime I can't switch to reader view, the console at Chrome DevTools shows the following error.
• although I can open the page in reader view in incongnito mode.

Readability.js:1019 Uncaught TypeError: Cannot read property 'tagName' of null
    at Readability._grabArticle (Readability.js:1019)
    at Readability.parse (Readability.js:1818)
    at Readability.parse (wrapper.js:41)
    at wrapper.js:78

It failed at the following code:

        var scoreThreshold = lastScore / 3;
        while (parentOfTopCandidate.tagName !== "BODY") { // failed at this line
          if (!parentOfTopCandidate.readability) {
            parentOfTopCandidate = parentOfTopCandidate.parentNode;
            continue;
          }

[rNeomy]

Please provide a sample page with the issue. btw, I am updating the Readability.js lib. So it might have already been fixed.