bevyengine/bevy · error

Backing data buffer must have been uploaded by now

Error message

Backing data buffer must have been uploaded by now

What it means

Panic while building bind group entries for data buffers: the backing GPU uniform buffer for a bindless data buffer slot was absent from the uploaded buffers map. The buffer should have been uploaded during prepare; its absence indicates a preparation-order bug.

Source

Thrown at crates/bevy_render/src/material_bind_groups.rs:1707

                    }
                    BindingResourceArray::TextureViews(ref texture_views) => {
                        BindingResource::TextureViewArray(&texture_views[..])
                    }
                    BindingResourceArray::Samplers(ref samplers) => {
                        BindingResource::SamplerArray(&samplers[..])
                    }
                },
            });
        }

        // Create bind group entries for any data buffers we're managing.
        for data_buffer in self.data_buffers.values() {
            bind_group_entries.push(BindGroupEntry {
                binding: *data_buffer.binding_number,
                resource: data_buffer
                    .buffer
                    .buffer()
                    .expect("Backing data buffer must have been uploaded by now")
                    .as_entire_binding(),
            });
        }

        self.bind_group = Some(render_device.create_bind_group(
            Some(label),
            &pipeline_cache.get_bind_group_layout(bind_group_layout),
            &bind_group_entries,
        ));
    }

    /// If this bind group contains a [`ShaderBuffer`], and the shader buffer
    /// has changed, marks the bind group as invalid so that it'll be rebuilt.
    ///
    /// Shader buffers are assets that can legally be updated to point to a
    /// different raw buffer. This will happen when, for example, the shader
    /// buffer grows. We must detect this circumstance and rebuild the bind
    /// group when it happens.

View on GitHub (pinned to 396ca72708)

Solutions

1. Report as a Bevy engine bug with a reproducing project
2. Ensure prepare/upload runs before bind group creation in custom pipelines

When it happens

Trigger: Thrown at crates/bevy_render/src/material_bind_groups.rs:1707 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/8432546954a94d89. Report an issue: GitHub.