Issue Summary

The configuration buttons within the Slack for Confluence Data Center (official) Marketplace App from Atlassian are not responsive and are unclickable due to the introduction of the Velocity method Allowlist in Confluence 9

Existing configurations persist if you've upgraded Confluence but cannot be edited

Steps to Reproduce

1. Install Confluence 9.3.1+
2. Install Slack for Confluence Data Center (official)
3. > General configuration > Slack integration > Setup integration
4. Try to edit or interact with any of the fields or buttons

Expected Results

You're able to interact with the configurations and UI. Sample gif from Confluence 5.8.19:

Actual Results

The buttons on the UI do nothing:

The below exception is thrown in the atlassian-confluence.log file:

2025-05-16 17:31:06,118 WARN [http-nio-6931-exec-9 url: /c931/plugins/servlet/slack/configure; user: admin] [velocity] log Invocation blocked as method is not allowlisted: com.atlassian.confluence.plugins.slack.spi.impl.ConfluenceSlackPluginResourceProvider#getPluginKey()
 -- url: /c931/plugins/servlet/slack/configure | userName: admin | referer: http://localhost:6931/c931/admin/browseshortcuts.action | traceId: 448d0e6891c7c23e

Nothing is logged in the browser Console or Network tab when clicking buttons in the UI

Workaround

Follow our Configuring System Properties document to add the following system property:

-Datlassian.velocity.method.allowlist.extra=com.atlassian.confluence.plugins.slack.spi.impl.ConfluenceSlackPluginResourceProvider#getPluginKey\(\)