bevyengine/bevy · error

DiagnosticsOverlayContents has been tempered with. Parent wa

Error message

DiagnosticsOverlayContents has been tempered with. Parent was not a DiagnosticsOverlay.

What it means

Panic in rebuild_diagnostics_list: a DiagnosticsOverlayContents entity's parent entity does not have a DiagnosticsOverlay component as the overlay UI builder expects. This only happens if user code has re-parented or altered the internally-spawned overlay hierarchy, which the overlay relies on.

Source

Thrown at crates/bevy_dev_tools/src/diagnostics_overlay.rs:306

#[derive(Component)]
struct DiagnosticsOverlayHeader;

/// Section of the overlay that will have the diagnostics
#[derive(Component)]
struct DiagnosticsOverlayContents;

fn rebuild_diagnostics_list(
    mut commands: Commands,
    diagnostics_overlays: Query<&DiagnosticsOverlay>,
    diagnostics_overlay_contents: Query<(Entity, &ChildOf), With<DiagnosticsOverlayContents>>,
    diagnostics_store: Res<DiagnosticsStore>,
    style: Res<DiagnosticsOverlayStyle>,
) {
    for (entity, child_of) in diagnostics_overlay_contents {
        commands.entity(entity).despawn_children();

        let Ok(diagnostics_overlay) = diagnostics_overlays.get(child_of.get()) else {
            panic!("DiagnosticsOverlayContents has been tempered with. Parent was not a DiagnosticsOverlay.");
        };

        for (i, diagnostic_overlay_item) in diagnostics_overlay.items.iter().enumerate() {
            let maybe_diagnostic = diagnostics_store.get(&diagnostic_overlay_item.path);
            let diagnostic = maybe_diagnostic
                .map(|diagnostic| {
                    format!(
                        "{}{}",
                        diagnostic_overlay_item
                            .statistic
                            .fetch(diagnostic)
                            .map(|sample| format!(
                                "{:.prec$}",
                                sample,
                                prec = diagnostic_overlay_item.precision
                            ))
                            .unwrap_or("No sample".to_owned()),
                        diagnostic.suffix

View on GitHub (pinned to 396ca72708)

Solutions

1. Avoid modifying the diagnostics overlay entity hierarchy
2. Rebuild the overlay via DiagnosticsOverlayPlugin instead of moving its entities

When it happens

Trigger: Thrown at crates/bevy_dev_tools/src/diagnostics_overlay.rs:306 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of bevyengine/bevy@396ca72708 (2026-08-20). Data as JSON: /api/errors/aeec481b8c657c54. Report an issue: GitHub.