Inspect `violations` for specific rule identifiers. Use `OpenOptions::convert_to_pdfa()` to auto-repair, or fix the source document before validation.

E-SECURITY-DECRYPTION-FAILED

Error::DecryptionFailed

Decryption failed — wrong password or unsupported algorithm.

Supply the correct password via `OpenOptions::password()`. Check `reason` to distinguish wrong-password from unsupported-algorithm cases.

E-SECURITY-INVALID-SIGNATURE

Error::InvalidSignature

A digital signature is invalid.

The signature in `field` failed verification. Check `reason` for details. Do not trust the document content if integrity is required.

E-LICENSE-INVALID

Error::InvalidLicense

License key is malformed or expired.

Re-issue the license key or call `activate_license()` again with a valid key. Check `reason` for the specific parse failure.

E-LICENSE-EXPIRED

Error::LicenseExpired

License key is well-formed and signed, but its `expires_at` is in the past. Surfaced by the signed-payload pathway only — mock `tier:X` keys have no expiry and never produce this variant.

Renew the license — the `expires_at` unix timestamp in the payload is in the past. Visit https://pdfluent.com/pricing or contact sales for a refreshed key.

E-LICENSE-INVALID-SIGNATURE

Error::LicenseInvalidSignature

License key is structurally a signed JSON payload but the Ed25519 signature does not verify against the configured public key. Indicates either a tampered payload or a payload signed by a different pr

The signed payload does not verify against the configured public key. Either the payload was tampered, or it was signed with a different private key than the verifier expects. Re-download the license file from PDFluent and try again; if the issue persists, con

E-LICENSE-RATE-LIMITED

Error::LicenseRateLimited

A license-enforced rate or usage limit was exceeded at runtime. Returned by `LicenseGuard::record_*` calls during operation; not an activation-time error. Carries the metered resource, used value, and

A licence-enforced rate or usage cap was reached. Inspect `resource`, `used`, and `limit` to identify which cap fired. Either upgrade the tier or wait for the metering window to reset.

E-EDIT-TEXT-FAILED

Error::TextEditFailed

A text-edit transaction failed (see [`crate::text_edit`] for the typed per-edit errors this message summarizes).

TBD

E-ENV-UNSUPPORTED-ON-WASM

Error::UnsupportedOnWasm

Operation is not supported in WebAssembly builds.

This operation (`operation`) cannot run in a WASM32 environment. Use the server-side API or guard with `#[cfg(not(target_arch = "wasm32"))]`.

E-ENV-MISSING-DEPENDENCY

Error::MissingDependency

A native dependency is required but not installed or discoverable.

Install the missing native library (`dep`) following `install_hint`. Ensure the library is on `LD_LIBRARY_PATH` / `DYLD_LIBRARY_PATH`.

E-BUDGET-MEMORY-EXCEEDED

Error::MemoryBudgetExceeded

Memory budget set via [`crate::OpenOptions::strict_memory_limit`] exceeded.

Raise the memory limit via `OpenOptions::strict_memory_limit()`, or process the document in smaller chunks.

E-BUDGET-RESOURCE-LIMIT

Error::ResourceLimitExceeded

A configured [`ProcessingLimits`](pdf_engine::ProcessingLimits) resource cap was exceeded while loading or processing the document. Returned when the caller has set a limits object via [`crate::OpenOp

Inspect `kind` to identify which cap fired, then raise the corresponding `ProcessingLimits` field. For untrusted input, keep limits tight and reject oversized files at the ingestion layer.

E-UNSUPPORTED

Error::Unsupported

The requested operation is not supported for this document or in this build.

Read the message: it names what was asked for. Either the document lacks the structure the operation needs, or the capability is not part of this build.

E-INTERNAL

Error::Internal

Internal safety-net. Should never fire under normal operation.

This should never occur under normal operation. File a bug report at https://pdfluent.com/support including `message` and `crate_version`.