Error reference / stateDiagram-v2
A transition between two states uses a single dash instead of stateDiagram's arrow (-->), the same class of mistake as the flowchart single-dash trap.
Parse error on line 3:
...> State1 State1 - State2 State2
----------------------^
Expecting 'SPACE', 'NL', 'DESCR', '-->', ... got 'INVALID'stateDiagram-v2 transitions require the two-dash arrow, State1 --> State2, same as flowcharts. A single dash isn't a recognized transition token, so the parser stops right after it.
This usually happens when copying a relationship from a different diagram type, or typing quickly and dropping a character.
Use --> between every pair of states, including transitions into and out of [*] (the start/end marker).
Fails to parse
stateDiagram-v2
[*] --> State1
State1 - State2
State2 --> [*]Renders correctly
stateDiagram-v2
[*] --> State1
State1 --> State2
State2 --> [*]A node ID exactly matches a Mermaid keyword (call, click, or href) and is referenced without a shape, so the parser reads it as a click-callback token instead of a node name.
A node's square-bracket label was never closed, so the parser runs into the next node's opening bracket before it finds the one it was expecting.
A square-bracket label contains a raw ( or ), which Mermaid reads as the start of a different node shape rather than as label text.