mozilla/pdf.js · error · Error

The overlay does not exist.

Error message

The overlay does not exist.

What it means

Thrown by OverlayManager.open when the dialog passed has never been registered (not in the #overlays WeakMap). open() requires a prior register() call to establish the overlay's metadata and cancel handler.

Source

Thrown at web/overlay_manager.js:54

      throw new Error("The overlay is already registered.");
    }
    this.#overlays.set(dialog, { canForceClose });

    dialog.addEventListener("cancel", ({ target }) => {
      if (this.#active === target) {
        this.#active = null;
      }
    });
  }

  /**
   * @param {HTMLDialogElement} dialog - The overlay's DOM element.
   * @returns {Promise} A promise that is resolved when the overlay has been
   *                    opened.
   */
  async open(dialog) {
    if (!this.#overlays.has(dialog)) {
      throw new Error("The overlay does not exist.");
    } else if (this.#active) {
      if (this.#active === dialog) {
        throw new Error("The overlay is already active.");
      } else if (this.#overlays.get(dialog).canForceClose) {
        await this.close();
      } else {
        throw new Error("Another overlay is currently active.");
      }
    }
    this.#active = dialog;
    dialog.showModal();
  }

  /**
   * @param {HTMLDialogElement} dialog - The overlay's DOM element.
   * @returns {Promise} A promise that is resolved when the overlay has been
   *                    closed.
   */

View on GitHub (pinned to 5903d58d58)

Solutions

1. Call await OverlayManager.register(dialog) before OverlayManager.open(dialog).
2. Keep a single cached element reference and reuse it for both register and open.
3. Avoid re-querying the DOM (querySelector) at open time if the element may have been swapped.

Example fix

// before
OverlayManager.open(document.getElementById('myDialog'));

// after
const dialog = document.getElementById('myDialog');
await OverlayManager.register(dialog);
await OverlayManager.open(dialog);

const dialog = document.getElementById('myDialog');
await OverlayManager.register(dialog); // ensure registered
await OverlayManager.open(dialog);

When it happens

Trigger: Calling open(dialog) before register(dialog), or passing a different element reference than the one registered (e.g. re-querying the DOM yields a new node).

Common situations: Forgetting to register, registering a stale element reference, or the element being replaced/recreated after registration.

Related errors

• Not enough parameters.
• The overlay is currently not active.
• Cannot use more than one PDFWorker per port.
• Canvas is not specified
• The overlay is already registered.

AI-assisted analysis of mozilla/pdf.js@5903d58d58 (2026-08-13). Data as JSON: /api/errors/a1cbc167fcab83f1. Report an issue: GitHub.