We sometimes change the global ACI, even during maintenance releases.
The upgrade process does not modify global ACI, so this can result in two servers of the same version having different global ACI depending on their history.
This can cause problems if a customer's applications implicitly depended on global ACI in one version. Installing a new version of DJ could break their apps.
Administrators ought to be made more aware of changes to global ACI so they don't fall into this subtle trap. Can we add something to the release notes?