Attributes have open quote

What it means

The parser started reading a quoted attribute value and reached the end of the tag, the line, or the document without finding the matching quote. Everything after the opening quote is being swallowed as attribute text.

The most common real cause is a value that itself contains the same quote character — an unescaped apostrophe inside a single-quoted value, or a double quote inside a double-quoted one.

What usually causes it

• A quote character inside the value: title='Tom's feed'.
• A dropped closing quote, often after an edit or an interpolation.
• Mismatched quote styles: href="https://example.com'.
• A newline inside what was meant to be a short value, hiding the missing quote.

How to fix it

• Escape the quote as ' or ", or switch to the other quote style.
• Escape attribute values with a serializer rather than interpolating strings.
• Look at the tag on the reported line for an odd number of quote characters.

The same error elsewhere

Different parsers, same defect. If you arrived with one of these messages, you are in the right place.

• Xerces (Java)

  Open quote is expected for attribute "title" associated with an element type "image:image".

• libxml2 (PHP, lxml, Nokogiri)

  AttValue: " or ' expected

• expat (Python)

  not well-formed (invalid token)