Why can't my plugin find my parameters

Using one of the original examples for a plugin and copied that plugin to start working on another one.
I cannot seem to load any of the parameters though:

execute(Map<String, String> map

All of map is empty. Any idea what can cause this?
The parameters show up when adding the plugin, they just do not seem to make it to the execute function.

My thoughts were that if the xhtml content would show up well and the execute function was being called the parameters should make it but that does not seem to be the case.
Any hints to further debug this?

What type of plugin and module type? Can you provide code snippets?

This was a Confluence plugin. Figured it out yesterday, the issue was that I have commas in the default for the parameter. That broke it. I swapped them for other characters and surrounded the default parameter values with quotes. I had expected some more of an error or warning in the logs for this.