Some causes:

ARTIFACTORY: How to debug ‘unknown blob’ when pulling from a local docker repository

AuthorFullName__c
Loren Yeung
articleNumber
000005281
ft:sourceType
Salesforce
FirstPublishedDate
2022-05-22T11:26:02Z
lastModifiedDate
2024-03-10T07:46:49Z
VersionNumber
5

Clean up scripts based off last downloaded timestamps can cause this to happen; it is not advisable to use these kinds of scripts on a docker repository unless it cleans up the entire image rather than some layers.