The message "ArtifactUploadServiceAccount" means that FamilySearch restricted an uploaded memory. Notification went to the person who originally uploaded the memory, as well as anyone using the watch feature to monitor people tagged in the memory.
Unfortunately, no one responded to these messages, and the system deleted the memory.
Note: Patrons have 30 days to respond to a message about a restricted Memory. If they do not respond, the system automatically deletes the memory.
Related articles
What rules apply to uploading memories to FamilySearch.org?
Why does it say that my photo is restricted?