Error Codes

pdf-writer (structured errors: code / next_actions / retryable)

Code	Meaning / what to do
`INVALID_ARGUMENT`	Invalid argument
`DOC_NOT_FOUND`	Input PDF not found
`FONT_NOT_FOUND`	Bad font path
`INVALID_PDF`	Broken PDF
`ENCRYPTED_PDF`	Encrypted PDFs cannot be edited
`UNSUPPORTED_PDF_FEATURE`	Unsupported feature such as XFA
`FILE_TOO_LARGE`	Size limit exceeded
`SIGNED_PDF`	Signature guard → `preserveSignatures` / `allowBreakingSignatures`
`TAGGED_PDF`	Tag guard → `allowBreakingTags`
`FONT_REQUIRED`	CJK output needs a font → `fontPath` / `PDF_WRITER_FONT`
`MISSING_GLYPH`	Missing glyph → `onMissingGlyph`
`INTERNAL_ERROR`	Internal error