This message means that during the scanning of an .AB file, the label assigned to the block was found to duplicate one that was already used in that module. You can ignore this, but unique labels strengthen your system documentation.
--Scanning A/B PLC file 11328.AB Label 24 refers to both Module 1,13,28 Block 8271 and Module 1,13,28 Block 8270. Label 24 refers to both Module 1,13,28 Block 8293 and Module 1,13,28 Block 8270. Label 24 refers to both Module 1,13,28 Block 8296 and Module 1,13,28 Block 8270. Label 24 refers to both Module 1,13,28 Block 8310 and Module 1,13,28 Block 8270.
This error can be built directly into Hyperview. For more information, see the article Building error reports into the M14.