HTML Guide

An attribute could not be parsed from the HTML input, probably due to a typo. Check this guide for a related HTML issue.

The attribute xmlns:serif is not a valid namespace. This attribute is set by Affinity Designer on SVG exports.

The only permitted value for the xmlns attribute is http://www.w3.org/2000/svg.

The namespace declaration for an <svg> element is provided by the xmlns attribute like this:

<svg xmlns="http://www.w3.org/2000/svg">
  <!-- more tags here -->
</svg>

Although using https in the URL looks like it’s going to be more secure, in fact this URL is not used to connect it to, only to declare the namespace.

Check the syntax of the affected tag, it’s probably malformed and a < character inside has been interpreted as an attribute.

For example, this code might cause this issue:

<!-- Malformed img tag -->
<img src="photo.jpg" alt="smiling cat" < />

<!-- Fixed img tag -->
<img src="photo.jpg" alt="smiling cat" />

An invalid attribute has been found on an element. Check the affected tag to ensure attributes are well-formed, and if they are you can consider using custom data attributes.

The only permitted value for the xmlns:link attribute is http://www.w3.org/1999/xlink.

Although using https in the URL looks like it’s going to be more secure, in fact this URL is not used to connect it to, only to declare the namespace.

The text-anchor attribute is used within SVG elements like text or textPath to specify the alignment of text relative to a given point, but it’s not allowed on g container elements.

Here’s an example of how you can correctly use the text-anchor attribute on a <text> element in SVG:

<svg width="200" height="200">
  <text x="100" y="100" text-anchor="middle">Centered text</text>
</svg>

In this example:

• The text-anchor="middle" attribute is applied directly to the <text> element.
• It aligns the text in the middle horizontally around the specified x-coordinate.

You can use the text-anchor element with the SVG elements text, textPath, tref or tspan.

The allowed values for the text-anchor attribute are start, middle or end. The value none is not valid for this attribute.

A <pattern> element has been found with an invalid ID. Check the format of the ID and ensure it does not start with a digit, full stop (.) or hyphen (-).

The <pattern> element is used within <svg> elements, which use XML 1.0 syntax. That syntax specifies that valid IDs only include designated characters (letters, digits, and a few punctuation marks), and do not start with a digit, a full stop (.) character, or a hyphen-minus (-) character.

Quote characters used for attributes can use either single quotes (') or double quotes ("), and they must be properly matched, for example:

<p class="news">...</p>

A common cause for this issue is forgetting to use the equal sign (=), so the HTML parser wrongly believes the quote forms part of the attribute name, for example:

<p class "news">this is wrong</p>

A tag starting with <? has been found within the document, but it’s not supported. Probable causes can be:

• Copy-pasting the contents of an SVG file. If you do that, you should only paste the <svg>...</svg> part, but not the first line with <?xml...>.
• Unprocessed <?...> tags on server scripting languages like PHP, like <?php>

Learn more:

• [freeCodeCamp: How to Use SVG Images in CSS and HTML]https://www.freecodecamp.org/news/use-svg-images-in-css-html/)