CodeBlock Not Supported in ANSI Format
writer
CodeBlock elements cannot be rendered in ANSI terminal output.
Q-3-51 — CodeBlock Not Supported in ANSI Format
CodeBlock elements cannot be rendered in ANSI terminal output.
What this means
A code block is a fenced or indented region of pre-formatted text, typically used for source code. The ANSI writer (used when rendering to a terminal) does not yet support code blocks and emits the error rather than rendering an unstyled block.
The omission is intentional: faithful ANSI rendering of a code block needs syntax-highlighting integration that the writer does not yet have.
Why this happens
Your document contains a fenced or indented code block and you rendered to ANSI output.
How to fix
Render to a different output format if you need the code blocks visible. HTML output uses a syntax highlighter; markdown output preserves the fences for downstream tooling to highlight.