mermaid.initialize({
sequenceDiagram:{
...
}
})
has been changed to
mermaid.initialize({
sequence:{
...
}
})
In old versions you need to add CSS file to your HTML:
<link rel="stylesheet" href="mermaid.min.css">
or
<link rel="stylesheet" href="mermaid.forest.min.css">
Now it is not needed to do so. And there are no more CSS files in distrubtion files.
You just
mermaid.initialize({
theme: 'forest'
})
and it works like a charm.
This is because now the CSS is inline with SVG for portability.