I'm trying to run the 'detectUsageOfUnavailableAPI' operation of PreUpgradeTasks Mbean on AEM 6.3 but get the following error when doing so:
com.adobe.aem.upgrade.prechecks.mbean.impl.PreUpgradeTasksMBeanImpl Cannot login into repository:
org.apache.sling.api.resource.LoginException: Cannot derive user name for bundle com.day.cq.pre-upgrade-tasks  and sub service null
Does anyone know why this is so? Any user that needs to be configured before running these tasks?
Usually, this error is observed when the service user mapping is missing to the pre-upgrade bundle. Can you add the mapping as per below and check if you still get the same issue?
Thanks for the reply. But I'm still getting the same error even after this change.
Can you go to <host>:<port>/useradmin and check if "preupgrade-service" is an actual service user in AEM?