DirSync Pro leverages the 'member' attribute value in Active Directory for the Group object to locate all the group members. This attribute contains a list of the members and their DN-Distinguished Name values which can be used to identify where the member is located in the AD Forest.
In this case, DirSync Pro found group member " GROUPMEMBER1" and when it tries to locate that object at " OU=Groups,OU=Countryxyz,OU=Sites,DC=mars,DC=contoso,DC=com", the object is not found. Additionally, you can also validate by browsing to the defined DN path on the DC-Domain Controller configured with DSP-DirSync Pro to confirm the member does not exist with the configured DCs.
Essentially, DirSync was not able to find the object using the current domain controller, in this case it will mark the DCs as not available. Then DSP will try to use a different DC in the list that was configured in the profile and attempt to find it. Once the sync is in this condition, the group member lookup will be halted for the current group object member list that is processing and move on to the next group.
Typically, this will occur for medium to large environments where the members are arranged by geography within the AD Forest.
