# errors

## Classes

| Class | Description |
| ------ | ------ |
| [ChunkCountExceededError](/reference/filoz/filecoin-encryption-envelope/namespaces/errors/classes/chunkcountexceedederror/) | A chunk count derived from a plaintext or ciphertext length exceeds `MAX_CHUNK_COUNT`. |
| [CriticalHeaderError](/reference/filoz/filecoin-encryption-envelope/namespaces/errors/classes/criticalheadererror/) | A `crit` (label 2) listing was rejected — wrong bucket, wrong shape, or naming a label this profile does not understand or does not actually carry. |
| [EnvelopeError](/reference/filoz/filecoin-encryption-envelope/namespaces/errors/classes/envelopeerror/) | Base class for every error raised by this package. |
| [InvalidChunkSizeError](/reference/filoz/filecoin-encryption-envelope/namespaces/errors/classes/invalidchunksizeerror/) | `chunkSize` is not an integer within `[MIN_CHUNK_SIZE, MAX_CHUNK_SIZE]`. |
| [InvalidCiphertextLengthError](/reference/filoz/filecoin-encryption-envelope/namespaces/errors/classes/invalidciphertextlengtherror/) | `ciphertextLength` is not a valid ciphertext length for the given chunk size. |
| [InvalidNonceError](/reference/filoz/filecoin-encryption-envelope/namespaces/errors/classes/invalidnonceerror/) | A base nonce, chunk index, or last-chunk flag is not valid for per-chunk nonce derivation. |
| [InvalidPlaintextLengthError](/reference/filoz/filecoin-encryption-envelope/namespaces/errors/classes/invalidplaintextlengtherror/) | `plaintextLength` is not a non-negative safe integer, or the ciphertext length it implies is unrepresentable or past the encoded-object limit. |
| [MalformedEnvelopeError](/reference/filoz/filecoin-encryption-envelope/namespaces/errors/classes/malformedenvelopeerror/) | The envelope, or a value destined for one, does not match this package's wire profile. Raised on both paths: by encode when a caller's input would produce bytes this package could not read back, and by decode on anything the profile forbids. |
| [UnsupportedSchemeError](/reference/filoz/filecoin-encryption-envelope/namespaces/errors/classes/unsupportedschemeerror/) | The protected header's `alg` is not one of the schemes this package implements (`ALG_AES_256_GCM` or `ALG_CHUNKED_AES_256_GCM_STREAM`). |