503 cq AuthenticationSupport service missing. Cannot authenticate request.

Possible reason is missing Repository service. means that Oak repository service isn't registered successfully. In other words, repository isn't available to do authentication for Apache Sling. There might be numerous reasons behind repository not coming up.

Just check if you are starting the AEM as super/admin user.

Thanks

Wasil

Hi Thanks for the reply ...am starting aem as admin, yesterday my machine got shut abnormally and till last night everything is working fine ....that's the only thing which went wrong last day....will there be anything else which gets corrupted because of abnormal system shutdown which might have caused this???

You should refer to error.log and check for errors if anything could be fixed. If you have backup please restore.

Thanks

Wasil

Error.log is showing Authentication Service error apart from this there is no other error as no upgrade is done, I do not have current instance backup where I have my code that's the sole reason I need help to restore the instance  please

Try logging to this url http://localhost:4502/system/console/bundles

Bundles url is accessible and I do find all bundles are active from the start this issue happened

Create DEBUG logger for "org.apache.jackrabbit.oak.segment" in http://<host>:<port>/system/console/slinglog in a separate log file. Restart the instance, check what information we get there.

In the debug  log for oak segment I do see Segment not found error
org.apache.jackrabbit.oak.segment.SegmentNotFoundException

org.apache.jackrabbit.oak.segment.SegmentNotFoundException: Segment f5c15052-5c4c-4931-a8bd-e502ac2bb2fd not found

     at org.apache.jackrabbit.oak.segment.file.FileStore$8.call(FileStore.java:602)

     at org.apache.jackrabbit.oak.segment.file.FileStore$8.call(FileStore.java:542)

     at org.apache.jackrabbit.oak.segment.SegmentCache.getSegment(SegmentCache.java:95)

     at org.apache.jackrabbit.oak.segment.file.FileStore.readSegment(FileStore.java:542)

     at org.apache.jackrabbit.oak.segment.SegmentId.getSegment(SegmentId.java:125)

     at org.apache.jackrabbit.oak.segment.Record.getSegment(Record.java:70)

     at org.apache.jackrabbit.oak.segment.MapRecord.getEntry(MapRecord.java:160)

     at org.apache.jackrabbit.oak.segment.MapRecord.getEntry(MapRecord.java:192)

     at org.apache.jackrabbit.oak.segment.MapRecord.getEntry(MapRecord.java:192)

     at org.apache.jackrabbit.oak.segment.MapRecord.getEntry(MapRecord.java:192)

     at org.apache.jackrabbit.oak.segment.SegmentNodeState.getChildNode(SegmentNodeState.java:412)

     at org.apache.jackrabbit.oak.plugins.index.property.strategy.UniqueEntryStoreStrategy.count(UniqueEntryStoreStrategy.java:190)

     at org.apache.jackrabbit.oak.plugins.index.property.strategy.UniqueEntryStoreStrategy.count(UniqueEntryStoreStrategy.java:204)

     at org.apache.jackrabbit.oak.plugins.index.property.PropertyIndexPlan.<init>(PropertyIndexPlan.java:148)

Try Fix Inconsistencies in the repository when SegmentNotFound Issue is reported in AEM 6.x   or

Offline Compaction fails with SegmentNotFoundException & IllegalArgumentException

based on AEM version

You may take a backup just in case..

Other than backup is there anything in particular I can do under crx-quickstart to resolve this and get the instance back...because fully active nd working instance suddenly crashed but still I find all bundles r active ..please help