Troubleshooting
Data not showing
Use Firebug to verify that there are no errors and that data is getting to the browser correctly. If it is not showing then it's usually due to a missing class in your stylesheet. Make sure that the label you receive in the data has an equivalent class name in the CSS file. For example, if you send data with 'geneModel' and 'exon' as feature names, then your CSS must have classes for 'geneModel' and 'exon'.
Finding configuration options
Each plugin (track) offers different configuration options. To find out what options are available you will need to read the documentation for the plugin in question. A list of these plugins is available here.
Bad comma placement
The config file is a Javascript object and, as such, must be properly formed. Object properties must be separated by commas, as must elements in an array. A common mistake is to add a comma after the last item in an object or array, or to miss a comma between two entries. More information about formatting can be obtained from JSON.org.
XHR request error when connecting to a service
This is a consequence of the same origin policy, a security mechanism in modern browsers that prevents cross-site requests. To get around this, you will need to configure your server as a reverse proxy. For more information, see configuring a reverse proxy.
Some other problem
I strongly recommend using Firefox with the Firebug extension enabled. This will quickly identify the exact source of errors in most cases. If you can't quickly resolve the problem, please contact me and I will see what I can do to help.

