Add-ons might stop working if confluence-users group doesn't have access on Confluence

Issue Summary

3rd Party Add-ons stops working if default group isn't confluence-users

Steps to Reproduce (example with Slack, but same bug can happen with any other addons)

1. In an instance with Slack integration enabled, create a new group - abc
2. Grant this group the "default" status and add it to Confluence product access
3. Remove product access and default status from confluence-users

Expected Results

Integration still works as expected.

Actual Results

The below error is observed.

Something went wrong while xxxxx. Please try again later or contact support.
Error code: UNEXPECTED_ERROR
Error ID: xxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxxx

This happens because the Slack Integrations user (confluence-chats-integration@connect.atlassian.com) adds itself to confluence-users and atlassian-addons. Since none of those groups are granting it product access to Confluence, it doesn't work.

Workaround

Contact Support to add the system user (product member role) to your default group with the help of an internal script.