Diagram error messages
Most errors come from the renderer for the language you are using, which means they read like that language's errors rather than ours. That is a feature: the message usually points at the exact line.
The table below covers the categories, and what each one usually means in practice.
#What you are seeing
An error message shown instead of the diagram.
An error in the editor while typing.
An error that appears only for some readers.
#Work through these in order
Check | What it means and what to do |
|---|---|
A syntax error naming a line | The source has a mistake at that line. The language reference pages have working examples to compare against. |
A parse error with no line | Usually the wrong language: source detected as one language but written in another. |
A timeout | The diagram is too large or too slow to render. Simplify or filter it. |
Nothing to render | An empty diagram, or one whose source failed to load. |
A permissions error | The reader cannot see the page storing the source. This is expected behaviour for references. |
A renderer unreachable error | If your site uses a self-hosted renderer, it is not responding. |
#A few things that catch people out
Check the language first. A Mermaid diagram detected as Graphviz produces confusing errors.
Errors from TikZ are TeX errors, which are verbose and often point one line further on than the real mistake.
If a diagram renders in the editor but errors on the page, that is worth reporting rather than working around.
#Related
Most of these take under a minute.
