theonedev/onedev · error · MarkupNotFoundException

Markup not found for Component:

Error message

Markup not found for Component: 

What it means

During internalRender() Wicket calls getMarkup() and throws MarkupNotFoundException when the component cannot resolve any markup (no associated markup file, no <wicket:fragment> entry, or component not attached to the markup hierarchy). Every rendered component must have markup available before rendering begins.

Source

Thrown at server-core/src/main/java/org/apache/wicket/Component.java:2389

			if (exception != null)
			{
				throw exception;
			}
		} finally {
			HierarchicalContext.pop();
		}
	}

	/**
	 * Performs a render of this component as part of a Page level render process.
	 */
	private void internalRender()
	{
		// Make sure there is a markup available for the Component
		IMarkupFragment markup = getMarkup();
		if (markup == null)
		{
			throw new MarkupNotFoundException("Markup not found for Component: " + toString());
		}

		// MarkupStream is an Iterator for the markup
		MarkupStream markupStream = new MarkupStream(markup);

		// Flag: we started the render process
		markRendering(true);

		MarkupElement elem = markup.get(0);
		if (elem instanceof ComponentTag)
		{
			// Guarantee that the markupStream is set and determineVisibility not yet tested
			// See WICKET-2049
			((ComponentTag)elem).onBeforeRender(this, markupStream);
		}

		// Determine if component is visible using it's authorization status
		// and the isVisible property.

View on GitHub (pinned to d44925c47c)

Solutions

1. Verify a markup file (same name as the class, .html) exists next to the component class in the same package.
2. Check the HTML contains a tag with wicket:id matching the component's getId().
3. For Fragment, ensure markupProvider's markup contains <wicket:fragment wicket:id="..."> with the right id.
4. Clear Wicket's markup cache / redeploy so new markup files are picked up (getResourceSettings().setCachingStrategy).
5. If the component renders itself (e.g. Label via the body), ensure the parent's markup stream still has its tag; check that no code removed the tag from markup.

Example fix

// before
class MyPanel extends Panel {} // MyPanel.html missing
// after
class MyPanel extends Panel {} // plus src/main/java/com/app/MyPanel.html with <wicket:panel>...</wicket:panel>

if (component.getMarkup() == null) { throw new AssertionError("Missing markup for " + component.getId() + "; check Foo.html and wicket:id"); }

boolean hasMarkup(Component c) { return c.getMarkup() != null; }

try { component.render(); } catch (MarkupNotFoundException e) { log.error("Check that class-named HTML file exists in same package and has wicket:id " + component.getId()); }

When it happens

Trigger: Rendering a component whose markup file (Foo.html) is missing or misnamed; a Fragment rendered without add(new Fragment(...)) or with wrong markupId; a Panel placed where no markup tag has its wicket:id; misconfigured markup loading after moving packages; calling component.render() manually outside a page with associated markup.

Common situations: HTML file placed in wrong package/resource folder so it's not on the classpath; renamed Java class without renaming the HTML file; markup caching stale after redeploy; adding a component to a page but forgetting the wicket:id in HTML; using Fragment with a markup provider that lacks the fragment id.

Understand the failure class

Background: 'Could not be found', 'does not exist', 'not found in database': the resource-not-found family when an ID, slug, key, or URI lookup comes back empty — this error's family across 20 libraries.

Related errors

• Markup not found. Component:
• Markup id set on a component that is usually not rendered in
• Placeholder tag set on a component that is usually not rende
• Cannot determine Markup. Component is not yet connected to a
• has not been properly detached. Something in the hierarchy

AI-assisted analysis of theonedev/onedev@d44925c47c (2026-09-06). Data as JSON: /api/errors/4cf2d4fc5b1cd0c1. Report an issue: GitHub.