Pumpkin-MC/Pumpkin · error · LoaderError

Invalid loader data

Error message

Invalid loader data

What it means

This is LoaderError::InvalidLoaderData. It means the loader was given data it considers invalid — e.g. the loader descriptor/data blob passed when creating or configuring a loader does not match the expected format. The loader cannot proceed with malformed loader data.

Solutions

1. Fix the loader configuration/data to match the documented format
2. Regenerate the plugin package with the official build tooling
3. Compare with a known-good loader configuration example
4. Validate any hand-edited config files for typos or missing fields

Example fix

null

// validate loader data shape before constructing the loader
assert!(!loader_data.is_empty(), "loader data must not be empty");

null

match Loader::from_data(data) {
    Err(LoaderError::InvalidLoaderData) => eprintln!("bad loader data; regenerate with official tooling"),
    Ok(l) => l,
    Err(e) => return Err(e),
}

When it happens

Trigger: Raised when constructing or configuring a loader with data that fails validation (wrong format, missing required parts, wrong type).

Common situations: Server/plugin configuration pointing a loader at wrong or corrupted data; hand-edited loader configuration; a plugin packaging tool producing a non-conforming archive.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

• Failed to load library
• Missing plugin metadata
• Missing plugin entrypoint
• Plugin initialization failed
• Runtime error

AI-assisted analysis of Pumpkin-MC/Pumpkin@8d4639e25a (2026-09-09). Data as JSON: /api/errors/c1913225997b9d5d. Report an issue: GitHub.

Appendix: source

Thrown at crates/pumpkin/src/plugin/loader/mod.rs:54

/// Unified loader error type
#[derive(Error, Debug)]
pub enum LoaderError {
    #[error("Failed to load library: {0}")]
    LibraryLoad(String),

    #[error("Missing plugin metadata")]
    MetadataMissing,

    #[error("Missing plugin entrypoint")]
    EntrypointMissing,

    #[error("Plugin initialization failed: {0}")]
    InitializationFailed(String),

    #[error("Runtime error: {0}")]
    RuntimeError(String),

    #[error("Invalid loader data")]
    InvalidLoaderData,

    #[error(
        "Plugin was built for an incompatible API version. Please rebuild it against this Pumpkin build."
    )]
    ApiVersionMissing,

    #[error(
        "Plugin API version mismatch (plugin {plugin_version}, server {server_version}). Please rebuild it against this Pumpkin build."
    )]
    ApiVersionMismatch {
        plugin_version: u32,
        server_version: u32,
    },

    #[error("Wasm plugin initialization error: {0}")]
    WasmInitializationError(#[from] PluginInitError),
}

View on GitHub (pinned to 8d4639e25a)