This message means that signals from more than one source are being brought into a connector at the coordinates indicated.
This message is often cosmetic. Opening up the sheet in Composer or WinCAD will allow you to remove the extraneous lines and connectors until a single path remains.
When this message mentions two different sources, it is clear that only one works. You can find out which one and resolve accordingly.
--Scanning drawing 9570357A.CAD More than one input to connector at 1600,2600: Block 1788 (FC 129) and Block 1788 (FC 129).
You can see that the extraneous line from block 1788 to S1 of block 1793 causes this message.
It appears that the signal from the two function codes shown are coming into a connector at the coordinates indicated. More than one input to connector at 6860,5960: Block 1606 (FC 30) and Block 1607 (FC 66).
This error can be built directly into Hyperview. For more information, see the article Building error reports into the M14.