Using ExtensionPoints from another plugin

Hi, I am struggling using the ExtensionPoint system. I have defined an extensionPoint in a plugin, and I want to use this extension point in another plugin. I'm following all the guidelines and I'm actually **able** to use the extension point from within the first plugin.

However it doesn't work on the other plugin, the method `getExtensions()` returns empty no matter what I do, and I have no clue debugging it.

Here's the code:

public static final ExtensionPointName<BundledThemeEP> EP_NAME =
    ExtensionPointName.create("com.chrisrm.idea.MaterialThemeUI.bundledTheme");

<extensions defaultExtensionNs="com.chrisrm.idea.MaterialThemeUI">
    <bundledTheme name="Mario" path="/themes/mario" icon="/icons/mario.png"/>
    <bundledTheme name="Luigi" path="/themes/luigi" icon="/icons/luigi.png"/>
</extensions>

Am I missing anything?