Markdown copy fails with `e is null`

[akaihola]

I did the following on Firefox:

• copy the md.min.js script from https://github.com/ryanschiang/claude-export/blob/main/dist/md.min.js using the Copy raw file icon
• open a Claude 3.5 Sonnet chat (URL is like https://claude.ai/chat/<uuid>)
• open the JS console by hitting F12 and clicking on the Console tab
• paste and execute the md.min.js script by hitting Ctrl-V and Enter

I got the following error:

Uncaught TypeError: e is null    debugger eval code:1:1191
    exports debugger eval code:1
    <anonymous> debugger eval code:1
    <anonymous> debugger eval code:1
    <anonymous> debugger eval code:1

[akaihola]

I un-minified md.min.js using unminify and ran that on the same chat. Now the error is:

Uncaught TypeError: e is null    debugger eval code:60:30
    exports debugger eval code:60
    <anonymous> debugger eval code:81
    <anonymous> debugger eval code:157
    <anonymous> debugger eval code:158

In the un-minified script, the mentioned lines with some context are:

    55              361: (e) => {
    56                  e.exports = function () {
    57                      var e = document.querySelector("div.flex-1.flex.flex-col.gap-3.px-4.pt-16"),
    58                          t = document.querySelector("button[data-testid='chat-menu-trigger']"),
    59                          n = t ? t.textContent : "";
**  60                      return {
                                elements: e.querySelectorAll(
                                    "div.font-claude-message, div.font-user-message"
                                ),
                                title: n
                            };
    61                  };
    62              },

(the word elements on line 60 starts in column 30)

    76      (e = r(255)),
    77          (t = r(380)),
    78          (n = r(361)),
    79          (function () {
    80              var o = "",
**  81                  a = n(),
    82                  r = a.elements,
    83                  c = a.title,
    84                  i = t();

   153                      f.nodeType === Node.TEXT_NODE && (o += "\n");
   154                  }
   155              }
   156              e(console, "md", c), console.save(o);
** 157          })();
** 158  })();

(script ends on line 158)