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Invalid Content

Your content is validated by Paligo when you attempt to save a topic and/or when you manually validate a topic. If Paligo detects that your content breaks the applied rules, it displays an error message.

The document had some validation errors dialog. The message tells you that the content has some validation errors and you should look at the validation panel to find out about them.

You can find information about the errors in the Validation panel on the right-hand side of the editor.

The validation panel. It shows three headings - Docbook validation, paligo recommended rules, and Schematron validation. Under each heading is a list of the validation errors.

Paligo adds a red highlight to the elements that contain invalid content.

A Paligo topic that contains validation errors. A section is highlighted in red as it contains an error.

The most common reasons for a topic being invalid are that its content:

Breaks the Paligo XML Schema Rules

Paligo XML schema validation errors are usually due to the incorrect positioning or ordering of elements. To make your topic valid, check that the content follows the Paligo XML Schema Rules which are based on DocBook (see

Invalid attributes and attribute values can also result in Paligo XML schema validation errors. To check for those, see Breaks the Rules for Attribute Values.

Breaks the Schematron Rules

If you have a Schematron validation error, it means that there are custom rules in place in your Paligo instance. These rules are set in a Schematron file. To find out what rules your content is breaking, you will need to find out what rules the Schematron defines.

You could ask whoever is responsible for uploading and maintaining the Schematron file. If that is not possible, you can ask someone with Schematron experience to view the Schematron file and figure out what rules are in place. The location of the Schematron file is explained in Upload Schematron Files to Paligo.

Breaks the Rules for Attribute Values

A topic can be invalid because it contains attributes that have values that are not supported. This can happen when:

  • An attribute value is added in the source code editor

  • Unsupported characters in your attribute values.

For example, if you have an orderedlist element, you can add a continuation attribute. In the Paligo editor, you can only select valid values for this, either: continues or restarts. But in the source code editor, you could set the value to "stop", which is invalid.


Invalid attribute values are part of the Paligo XML Schema Rules.

To fix invalid attribute values:

  1. For each attribute, use the Paligo editor to look at the values that are in place, and also the options that can be selected for the values. These are valid values for the attribute.

    Element attributes panel shows the orderedlist element has a continuation attribute. There are two possible values for the continuation attribute - continues and restarts.
  2. Use the source code editor to look at the values that are set for your attributes. If there are any invalid values, remove them and then use the Paligo editor to add a valid value.

    Source code view of a topic. A call out arrow points to code that has continuation="stops". The "stops" is an invalid value for the continuation attribute.

    To learn how to access the source code editor, see The Source Code Editor.