There were several noticed errors in error.log on both Author and Publish Instances.
- Author error.log:
*ERROR* aem-api-metrics FrameworkEvent ERROR (org.apache.felix.log.LogException: org.osgi.framework.ServiceException: ServiceFactory.getService() resulted in a cycle.)
org.apache.felix.log.LogException: org.osgi.framework.ServiceException: ServiceFactory.getService() resulted in a cycle.
*ERROR* org.apache.sling.engine.impl.SlingHttpContext handleSecurity: AuthenticationSupport service missing. Cannot authenticate request.
*ERROR* org.apache.sling.engine.impl.SlingHttpContext handleSecurity: Possible reason is missing Repository service. Check AuthenticationSupport dependencies.
- Publisher error.log
*ERROR* ROOT bundle org.apache.felix.scr:2.1.30 (32) Circular reference detected trying to get service
Analyzing the error logs, it has been noticed that at the time the errors appeared, the instances were still in Startup mode, not all bundles being started (For example: StartupListenerTracker Startup progress: 83% (bundles 489/587)).
Therefore the errors occurred as not all bundles were started.
During a restart, or anything that causes a restart such as installing or reinstalling bundles or packages that trigger a re-register of OSGi bundles, these kind of exceptions are common.
If the errors are noticed after an instance is fully started, all bundles being active, please open a ticket with Adobe Support for further investigation.