org.apache.jackrabbit.oak - Segment not found error

[JCR <jc...@proxymit.net>]

Hello

I experienced a fatal Oak error on my Sling version 12 instance 
(oak-core 1.42.0):

14.01.2026 09:55:29.142 *ERROR* [Apache Sling Repository Startup Thread 
#1] org.apache.jackrabbit.oak.segment.SegmentNotFoundExceptionListener 
Segment not found: 28c937e7-4125-4afc-a2c4-c12a7401edc1. SegmentId age=52ms
org.apache.jackrabbit.oak.segment.SegmentNotFoundException: Segment 
28c937e7-4125-4afc-a2c4-c12a7401edc1 not found
     at 
org.apache.jackrabbit.oak.segment.file.AbstractFileStore.readSegmentUncached(AbstractFileStore.java:295) 
[org.apache.jackrabbit.oak-segment-tar:1.42.0]
     ...

This happened after months of uptime...

I fixed this by removing the nodes concerned from the segmentstore with 
oak-run 1.42.0, according to this document: 
https://experienceleaguecommunities.adobe.com/t5/adobe-experience-manager/org-apache-jackrabbit-oak-segment-segmentnotfoundexception-in-my/m-p/665758

Now, the instance still does not come up, now with an oak security 
provider error:

14.01.2026 15:12:17.857 *INFO* [FelixStartLevel] 
org.apache.jackrabbit.oak.security.internal.SecurityProviderRegistration 
Trying to register a SecurityProvider...
14.01.2026 15:12:17.857 *INFO* [FelixStartLevel] 
org.apache.jackrabbit.oak.security.internal.SecurityProviderRegistration 
Aborting: preconditions are not satisfied: Preconditions(preconditions = 
[org.apache.jackrabbit.oak.security.authentication.token.TokenConfigurationImpl, 
org.apache.jackrabbit.oak.spi.security.user.action.DefaultAuthorizableActionProvider, 
org.apache.jackrabbit.oak.security.user.UserAuthenticationFactoryImpl, 
org.apache.jackrabbit.oak.security.authorization.AuthorizationConfigurationImpl, 
org.apache.jackrabbit.oak.spi.security.authorization.principalbased.impl.PrincipalBasedAuthorizationConfiguration, 
org.apache.jackrabbit.oak.security.principal.PrincipalConfigurationImpl, 
org.apache.jackrabbit.oak.security.authorization.restriction.RestrictionProviderImpl], 
candidates = 
[org.apache.jackrabbit.oak.security.authentication.token.TokenConfigurationImpl, 
org.apache.jackrabbit.oak.security.user.UserAuthenticationFactoryImpl, 
org.apache.jackrabbit.oak.security.principal.PrincipalConfigurationImpl, 
org.apache.jackrabbit.oak.security.user.RandomAuthorizableNodeName, 
org.apache.jackrabbit.oak.security.authorization.restriction.RestrictionProviderImpl])

... repeating 3 times, then ...

14.01.2026 15:12:18.020 *INFO* [FelixStartLevel] 
org.apache.jackrabbit.oak.segment.file.FileStore Creating file store 
FileStoreBuilder{version=1.42.0, 
directory=/opt/sling/launcher/repository/segmentstore, blobStore=null, 
binariesInlineThreshold=16512, maxFileSize=256, segmentCacheSize=256, 
stringCacheSize=256, templateCacheSize=64, 
stringDeduplicationCacheSize=15000, templateDeduplicationCacheSize=3000, 
nodeDeduplicationCacheSize=1048576, memoryMapping=true, 
offHeapAccess=false, gcOptions=SegmentGCOptions{paused=false, 
estimationDisabled=false, gcSizeDeltaEstimation=1073741824, 
retryCount=5, forceTimeout=60, retainedGenerations=2, gcType=FULL, 
compactorType=CHECKPOINT_COMPACTOR}}
[ERROR] Error while running launcher: null

What is the problem here and how can it be resolved?

Thanks for any pointer!

Best,
Juerg