Go to your model folder K:\AosService\PackagesLocalDirectory\XXXXX\XXXXX\AxReport

Find your report XML and save a copy for backup.
Run notepad as administrator and open your reports XML.
Search for your design name

              MyDesign  

Search again, this time for

<NoRowsMessage>

You might find this

                  </TablixHeader>
                  <TablixMembers>
                    <TablixMember />
                  </TablixMembers>
                </TablixMember>
              </TablixMembers>
            </TablixRowHierarchy>
            <NoRowsMessage>=Labels!@SYS300117</NoRowsMessage>

Replace with

                </TablixHeader>
                <Group Name="Details" />
                </TablixMember>
              </TablixMembers>
            </TablixRowHierarchy>
            <NoRowsMessage>=Labels!@SYS300117</NoRowsMessage>