Blogger Template Error Message: "XML document structures must start and end within the same entity."

Error Message

The error message on Blogger (HTML editor) looks like this:

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Why?

Because I accidentally deleted the closing CDATA section in a script.

It was supposed to be like so:

<script> // <![CDATA[ /* JavaScript lines here */ // ]]> </script>

And I — with my sleight of mouse-hand, selected one line too many — deleted the closing tag:

<script> // <![CDATA[ /* JavaScript lines here */ </script>

Then I saved the template.

XML was —

(XML.) Oi!

Aye? What?

(XML.) Must start and end within the same entity!

Which one?

(XML.) Read.

My script is fine, ya muppet! Save it. S. A. V. E.

(XML.) READ.

I did! Why is your message vague?

(XML.) R. E. A...

Fine.

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Solution

I was baffled by that because my script had everything escaped, the forbidden entities. I bloody checked the JavaScript code and nothing was suspicious. And then... I reread the error message more than thrice. Hm, the line number — skimmed the lines before that error reference... ☠️⚡

The solution was, well, simply —

put it back.

Then we can safely save the customised template.

It must be closed properly:

<script> // <![CDATA[ ⬅️ CDATA section opening. /* JavaScript lines here */ // ]]> ⬅️ This is the closure. </script>

Above is a case of mine, trouserless CDATA section. This can also appear when we forget to close a b:if (or any other tag) in a Blogger template.

The rules:

• Every opening tag must have a matching closing tag.
• Nested tags must also close in the right order.

Otherwise, XML will throw a tantrum.

CRYPTIC TANTRUM.

Imagine if a child did that. Cryptic? I mean, that would certainly be the changeling of a changeling.

The changeling within a changeling. Even the fairies would be... still indifferent. — Recursion, you say? (Sips tea. Flips fairy newspaper.)