> ## Documentation Index
> Fetch the complete documentation index at: https://learn.nextedy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Swimlane Expansion Issues

> Diagnose and resolve problems where clicking to expand or collapse a swimlane produces unexpected behavior — including expanding the wrong swimlane, no response, or inconsistent results across browsers.

***

## Symptoms

| Symptom                                                               | Likely Cause                                                          |
| --------------------------------------------------------------------- | --------------------------------------------------------------------- |
| Clicking a swimlane expands a different swimlane (often the last one) | Known browser-specific rendering bug                                  |
| Expand/collapse works in one browser but not another                  | Chrome vs Edge compatibility issue                                    |
| Swimlane toggle is intermittent — works sometimes, fails other times  | Same browser rendering issue                                          |
| All swimlanes appear expanded and cannot be collapsed                 | `collapsibleSwimlanes` parameter set to `false`                       |
| Swimlanes are not visible at all                                      | Assignment mode is set to `none`, or no items match swimlane criteria |

***

## Check the `collapsibleSwimlanes` Parameter

Before investigating browser issues, confirm that swimlane collapsibility is enabled in the widget configuration.

1. Open the Polarion page containing your Nextedy PLANNINGBOARD widget in edit mode.
2. Open the **Widget Parameters** panel.
3. Navigate to the **Swimlanes (Rows)** section.
4. Confirm that `collapsibleSwimlanes` is set to `true` (the default).

The property default is `true`. If it has been explicitly set to `false`, swimlanes will render as permanently expanded with no toggle control.

<Warning title="Whitespace sensitivity in capacity and swimlane parameters">
  Widget parameter values are whitespace-sensitive. A value of ` true` (with a leading space) will not be treated the same as `true`. Always verify there are no leading or trailing spaces when editing parameters directly.
</Warning>

***

## Address the Chrome Swimlane Expansion Bug

A confirmed browser-specific bug causes clicking to expand a swimlane to expand a **different swimlane** instead — typically the last swimlane in the list. This behavior is **intermittent** and has been reproduced in Chrome. Microsoft Edge does not exhibit this issue.

### Workaround: Use Microsoft Edge

The most reliable resolution is to switch from Chrome to Microsoft Edge for Planningboard sessions where swimlane expand/collapse interaction is required.

1. Open Microsoft Edge.
2. Navigate to the same Polarion page.
3. Verify that swimlane expand/collapse now responds to the correct swimlane.

<Warning title="Known issue: Chrome swimlane expansion">
  Clicking a swimlane header in Chrome may expand a different swimlane — usually the last one in the list — rather than the one you clicked. This is a known rendering issue in Chrome. No fix has been shipped for this issue. Use Microsoft Edge as the recommended browser for Planningboard if you rely on swimlane expand/collapse.
</Warning>

<Tip title="Refresh before switching browsers">
  If you have made planning changes in Chrome before encountering the issue, use the **Refresh** button (`#btnRefresh`) to reload the current board state from the server before switching to Edge. This ensures your changes are persisted and visible in Edge.
</Tip>

***

## Verify the Assignment Mode Is Set Correctly

Swimlane expansion is only meaningful when a swimlane assignment type is active. If the board uses `assignmentMode = none`, all items appear in a flat list with no swimlanes to expand or collapse.

```text theme={null}
Widget Parameters → Swimlanes (Rows) → Assignment Type
```

Confirm the **Assignment Type** is set to one of the supported modes:

* **Users (Assignee)** — one swimlane per assignee in the project
* **Parent Item** — one swimlane per parent work item
* **Enumeration Field** — one swimlane per field value
* **Project** — one swimlane per sub-project
* **SAFe assignment types** — for SAFe environments

If the assignment type is **No Swimlanes**, the board intentionally renders without rows — there is nothing to expand or collapse. See [No Swimlanes Mode](/planningboard/guides/swimlanes/no-swimlanes-mode) if this mode is intentional.

***

## Check Whether Empty Swimlanes Are Hidden

If swimlanes appear to be missing — rather than collapsed — the `showEmptySwimlanes` parameter may be hiding them.

The property default is `false`, meaning swimlanes with no matching work items are **not shown**. If a swimlane you expect to see is absent, either:

* No work items are currently assigned to that swimlane's criterion (e.g. no items assigned to that user or enum value), or
* The swimlane assignment criterion does not match any items given the current work-item query.

To confirm: temporarily set `showEmptySwimlanes = true` in the widget parameters. All swimlanes — including empty ones — will then appear on the board. If previously hidden swimlanes now show up empty, adjust your work-item query or swimlane assignment configuration rather than keeping `showEmptySwimlanes = true` in production.

<Tip title="Distinguish missing from collapsed">
  A collapsed swimlane shows a thin header bar. A completely absent swimlane — due to `showEmptySwimlanes = false` — leaves no visible trace. If you expect a swimlane and see nothing, check `showEmptySwimlanes` first before investigating the browser issue.
</Tip>

***

## Enumeration Field Swimlanes: Validation Error After Save

If you configured swimlanes using an **Enumeration Field** assignment type and see the error `field does not exist or is not of type enumeration` after saving:

<Warning title="Global enumeration custom fields may not be supported">
  Global enumeration custom fields (defined at the global level rather than at the project level) appear to have limited or unsupported status for Planningboard swimlanes. A global enum field may validate during initial configuration but fail after saving. If you encounter this error, use a **project-level enumeration custom field** instead. Contact Nextedy support if a global field is required for your workflow.
</Warning>

Steps to resolve:

1. Open **Widget Parameters → Swimlanes (Rows)**.
2. Note the **Field ID** value in the Enumeration Field configuration.
3. In Polarion Administration, confirm the field is defined at the **project** level (not global).
4. If the field is global, create an equivalent project-level enumeration field and reconfigure the widget parameter to reference that field ID.

See [Enumeration Field Swimlanes](/planningboard/guides/swimlanes/enum-swimlanes) for full configuration guidance.

***

## Decision Flow

```text theme={null}
Swimlane expansion not working as expected
            |
            v
  collapsibleSwimlanes = false?
  +-----------+-----------+
  Yes                    No
  |                       |
  Set to true             |
                          v
              Wrong swimlane expands (last one)?
              +-----------+-----------+
              Yes                    No
              |                       |
    Switch to Edge         Swimlane missing entirely?
    (Chrome bug)           +-----------+-----------+
                           Yes                    No
                           |                       |
              showEmptySwimlanes = false?    Refresh board,
              Set to true to check           check query
                           |
              Check assignment mode —
              is it 'none' / No Swimlanes?
```

***

## Verification

After applying a fix, confirm the behavior is resolved:

1. Reload the Planningboard page.
2. Click a swimlane header that is currently expanded.
3. Confirm **that specific swimlane** collapses — not another.
4. Click the same header again.
5. Confirm it expands back.

You should now see each swimlane header toggle only its own row, with the correct swimlane expanding or collapsing on each click. If you are on Edge and the behavior is correct, the Chrome issue is confirmed; consider making Edge the standard browser for Planningboard users in your team.

***

## See also

* [Configure Swimlanes (Rows)](/planningboard/guides/configuration/swimlanes-configuration) — widget parameters for swimlane assignment type and collapsibility
* [User and Assignee Swimlanes](/planningboard/guides/swimlanes/user-swimlanes)
* [Enumeration Field Swimlanes](/planningboard/guides/swimlanes/enum-swimlanes)
* [No Swimlanes Mode](/planningboard/guides/swimlanes/no-swimlanes-mode)
* [Common Errors](/planningboard/guides/troubleshooting/common-errors)
* [Scroll and Focus Behavior](/planningboard/guides/troubleshooting/scroll-behavior)

<Accordion title="Sources">
  **KB Articles**

  * Swimlane Assignment Types

  **Support Tickets**

  * [#6688](https://support.nextedy.com/helpdesk/tickets/6688)
  * [#5760](https://support.nextedy.com/helpdesk/tickets/5760)
  * [#6734](https://support.nextedy.com/helpdesk/tickets/6734)

  **Source Code**

  * `PlanningBoardWidgetDependenciesProcessor.java`
  * `PlanningBoardWidgetRenderer.java`
  * `PlanningBoardDataService.java`
  * `AssignmentMode.java`
  * `licenseReadonly.cy.ts`
</Accordion>