Does anybody know this problem is caused ?

Problem 76- Shared folder/book "User7" has a distribution list problem
Starting User-Defined Table check
User-Defined Table check complete
Starting address book sync
Address book sync complete
Starting PAB index check
PAB index check complete
Starting PAB duplicate book check
Duplicate book check complete
- checking Folder records
- Record 23991 updated successfully
- Record 23994 updated successfully
- Record 23996 updated successfully
- Record 24002 updated successfully
- Record 24004 updated successfully
- Record 24005 updated successfully
- Record 24006 updated successfully