web-item icon not showing up in production

[a.webster]

Hi,

I have a simple project-scoped plugin with a web-item which points to a web-panel. The plugin itself works fine however when I deploy the jar to a production server, the web-item icon doesn't show up whereas it does using the SDK. Any ideas ? Here's my atlassian-plugin.xml...

<?xml version="1.0" encoding="UTF-8"?>

<atlassian-plugin key="${atlassian.plugin.key}" name="${project.name}" plugins-version="2">

  <plugin-info> 
    <description>${project.description}</description>  
    <version>${project.version}</version>  
    <vendor name="${project.organization.name}" url="${project.organization.url}"/>  
    <param name="plugin-icon">images/pluginIcon.png</param>
  </plugin-info>

  <web-resource key="highlight-importer-resources" name="highlight-importer Web Resources">

    <dependency>com.atlassian.auiplugin:ajs</dependency>

    ... other resources

    <resource type="download" name="images/" location="/images"/>

    <context>highlight-importer</context>

  </web-resource>

  <web-item key="release-page" section="jira.project.sidebar.plugins.navigation" weight="300">

    <label>Highlight</label>
    <icon height="16" width="16">
      <link linkId="test-item" absolute="true">
        $webResourceManager.getStaticPluginResource("${project.groupId}.${project.artifactId}:highlight-importer-resources", "images/pluginIcon.png")
      </link>
    </icon>
    <link linkId="myLink">/projects/$pathEncodedProjectKey?selectedItem=com.atlassian.jira.jira-projects-plugin:highlight-import-panel</link>
    <condition class="com.atlassian.jira.plugin.webfragment.conditions.CanAdministerProjectCondition"/>

  </web-item>
   
  <web-panel key="highlight-import-panel" location="com.atlassian.jira.jira-projects-plugin:highlight-import-panel">
    <resource name="view" type="velocity" location="container.vm"/>
  </web-panel>

  <rest key="rest" path="/highlight" version="1"/>

</atlassian-plugin>

 Thanks!