Compiler is unavailable or times out
Check Letterpress.Compiler.status/1, the Node executable, the caller-owned
Letterpress.Compiler.Supervisor, and the per-call :compiler_timeout. A
failed request never licenses a fallback compiler. Retry only when the host's
authoring workflow says it is safe.
MJML or Liquid diagnostics point at old text
Return source_hash and document_version with every validation response and
pass both to the browser extension. Diagnostics from another source revision
are ignored.
A value is rejected in one location
Inspect the schema context. A url value may appear in a URL-bearing attribute
or be displayed as text, HTML text, or a subject, but a general text value
cannot enter a URL sink. CSS and color values must be compile-phase. Define
separate variables for context combinations outside the compatibility rules.
An artifact no longer decodes
Do not edit artifact JSON. Verify that the complete canonical artifact was
stored and that its content_sha256 and compiler fields were preserved. An
unknown artifact version requires an explicit compatible decoder or a
controlled recompilation from retained source.