OrchardCMS/OrchardCore · error · ArgumentException

page_title tag requires a segment argument

Error message

page_title tag requires a segment argument

What it means

The Liquid `page_title add_segment` tag requires a `segment` argument (the first positional argument or a named `segment:`) because it is the text added to the page title. When `arguments["segment", 0]` resolves to null — no positional or named segment supplied — the tag throws an ArgumentException with this message.

Solutions

1. Pass the segment as the first positional argument: `{% page_title 'My Section' %}`.
2. Or use the named form: `{% page_title segment:'My Section', position:'2' %}`.
3. If the segment comes from a variable, ensure the variable is assigned and non-null before the tag executes.

Example fix

// before
{% page_title position:'2' %}
// after
{% page_title 'My Section', position:'2' %}

{% if segment == blank %}{% // page_title add_segment requires a non-empty segment %}{% endif %}

When it happens

Trigger: Calling `{% page_title %}` with the add-segment style but omitting the segment, e.g. `{% page_title position:'2' %}` with no segment value, or `{% page_title add_segment:true %}` without `segment:`.

Common situations: Copy-pasted title-tag snippets with arguments stripped; a Liquid variable used as the segment that is null/undefined so the named argument lookup misses; typos like `segments:` instead of `segment:`.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• render_section tag requires a name argument
• Cannot override href with other properties
• Format of the link cannot be determined based on the…
• Zone not found while invoking 'render_section':
• An implementation of 'LiquidTemplateContext' is required

AI-assisted analysis of OrchardCMS/OrchardCore@4306c0717f (2026-09-13). Data as JSON: /api/errors/c7b831ce1dbaca03. Report an issue: GitHub.

Appendix: source

Thrown at src/OrchardCore/OrchardCore.DisplayManagement.Liquid/Tags/PageTitleSegmentsTags.cs:41

        return Completion.Normal;
    }

    public static async ValueTask<Completion> WriteAddSegmentAsync(IReadOnlyList<FilterArgument> argumentsList, TextWriter _1, TextEncoder _2, TemplateContext context)
    {
        var arguments = new NamedExpressionList(argumentsList);

        await AddSegmentInternalAsync(arguments, context);

        return Completion.Normal;
    }

    private static async Task<IPageTitleBuilder> AddSegmentInternalAsync(NamedExpressionList arguments, TemplateContext context)
    {
        var services = ((LiquidTemplateContext)context).Services;

        var titleBuilder = services.GetRequiredService<IPageTitleBuilder>();

        var segmentExpression = arguments["segment", 0] ?? throw new ArgumentException("page_title tag requires a segment argument");
        var segment = (await segmentExpression.EvaluateAsync(context)).ToStringValue();

        var positionExpression = arguments["position", 1];
        var position = positionExpression == null ? "0" : (await positionExpression.EvaluateAsync(context)).ToStringValue();

        titleBuilder.AddSegment(new HtmlString(segment), position);

        return titleBuilder;
    }
}

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