When I run mermaid 6.0.0 on the classDiagram example I get a picture as attached.

Hello. That looks like some styling is lost. Is the mermaid.css in place?
All other examples can be compiled without problems.
For this, I created a virtualenv, ran
npm install mermaid --save-dev
and which mermaid gives me
.virtualenvs/mermaid/bin/mermaid.
Specifying the -t option with the normal mermaid.css does help not either and the debug output looks like this: http://pastebin.com/y5vjp2jV
Not only in Mac, it is also failing in my ubuntu 16.04, with node v6.3.1, phantomjs 2.1.1, and mermaid 6.0.0. I get the same output =(
It is probably a parsing problem, when I use a %% before the diagram it fails completly, below is the diagram code as I used, and bellow it is the error message when running mermaid <file_name>:
%% A Class diagram
classDiagram
Class01 <|-- AveryLongClass : Cool
Class03 *-- Class04
Class05 o-- Class06
Class07 .. Class08
Class09 --> C2 : Where am i?
Class09 --* C3
Class09 --|> Class07
Class07 : equals()
Class07 : Object[] elementData
Class01 : size()
Class01 : int chimp
Class01 : int gorilla
Class08 <--> C2: Cool label
Output:
Num files to execute : 1
ready to execute png: class_diagram_example.png
CONSOLE: [17:38:07 (172)] Starting rendering diagrams (from line # in "")
CONSOLE: [17:38:07 (172)] Start On Load before: undefined (from line # in "")
CONSOLE: [17:38:07 (172)] Initializing mermaidAPI (from line # in "")
CONSOLE: [17:38:07 (172)] Setting conf gantt - useWidth (from line # in "")
CONSOLE: [17:38:07 (172)] Setting config: gantt useWidth to 1200 (from line # in "")
CONSOLE: [17:38:07 (174)] Detected classDiagram syntax (from line # in "")
CONSOLE: [17:38:07 (175)] {
"message": "Parse error on line 1:\n%% A Class diagramclassDiagram Cl\n------------------^\nExpecting 'CLASS_DIAGRAM', got 'NEWLINE'",
"hash": {
"text": "\n",
"token": "NEWLINE",
"line": 1,
"loc": {
"first_line": 1,
"first_column": 0,
"last_line": 1,
"last_column": 0
},
"expected": [
"'CLASS_DIAGRAM'"
]
},
"line": 49466,
"sourceURL": "phantomjs://code/mermaid.js",
"stack": "parseError@phantomjs://code/mermaid.js:49466:49\nparse@phantomjs://code/mermaid.js:49551:36\ndraw@phantomjs://code/mermaid.js:49179:13\nrender@phantomjs:/
/code/mermaid.js:58825:31\nrender@phantomjs://code/mermaid.js:58882:30\n_init@phantomjs://code/mermaid.js:58250:26\nexecuteInPage\n\nglobal code\nevaluateJavaScript@[
native code]\nevaluate@phantomjs://platform/webpage.js:390:39\nphantomjs://code/phantomscript.js:92:29\nforEach@[native code]\nglobal code@phantomjs://code/phantomscr
ipt.js:79:14"
} (from line # in "")
saved png: class_diagram_example.png
I've done some more research and I found an isolated testable environment, the most popular mermaid container in Docker Hub, which also is not able to correctly render a class diagriam such as:
Class03 *-- Class04
Resulting in the following image:

Still falling in atom-mermaid plugin.
same issue (6.0.0, 7.0.0) I've downloaded and use js and css on local machine.
os: win 7 64x
browser: chrome
update:
mermaid.forest.css contains required css classes, so diagram works with Forest theme.
Looks into the src/less/ folder, seems that only forest and neutral contains classDiagram.less.
The content in src/less/forest/classDiagram.less looks generic.
Could we copy it to src/less/default/ to build the style needed by classDiagram for default theme?
Good idea!
This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.
Most helpful comment
Not only in Mac, it is also failing in my ubuntu 16.04, with node
v6.3.1, phantomjs2.1.1, and mermaid6.0.0. I get the same output =(