Parentheses have a job in Mermaid flowcharts: they can define a node's shape. That is why text such as Build (beta) can be misread when pasted into an unquoted label. If the parentheses are part of the label, put the label in double quotes inside the node's shape markers.
This line is easy to mistake for ordinary text, but the punctuation may be parsed as flowchart syntax:
flowchart LR
Start --> Build[Build (beta)]Keep the square brackets for a rectangular node and quote the text inside them:
The node IDs are Start, Build, and Check. The words in quotes are display labels; changing those words does not require changing every arrow that refers to the node. If your original unquoted text happens to render in one Mermaid version, quotes still make the intended label unambiguous across renderers.
Do not quote or remove the outer parentheses when you want a rounded node:
Review("Review (editor)") has a rounded shape because of the outer parentheses. The inner (editor) is text because it is inside quotes. Similarly, Store[(Database)] uses Mermaid's shape syntax; it is not an instruction to print literal brackets and parentheses around a word.
There are two parsers when a Mermaid diagram sits in a Markdown document. Markdown sees the fenced code block; Mermaid then interprets the text inside the block. Escaping a Markdown link URL will not repair a Mermaid node label, and quoting a Mermaid label will not repair a Markdown link. For links and URLs outside a Mermaid fence, use the Markdown parentheses and brackets guide.
If the whole diagram displays as source code, check that the fence starts with three backticks and mermaid. If the viewer reports a syntax error, try the quoted-label form above first. Then check nearby arrows and whether every bracket or parenthesis used to define a node shape has a matching closer. Mermaid also supports character entity codes for labels with other troublesome punctuation; see its flowchart syntax reference.
Paste this complete block into a Markdown document:
If a larger diagram still fails, isolate the smallest failing line before changing the whole chart. The broken Mermaid diagram guide covers other syntax errors and the Quick Fix workflow.
Preview a Markdown file with Mermaid to check the rendered labels, not just the source.