Altium - Handling Multiple net names for buses
Here you can find how to solve your problem (Altium Website)

The problem you are describing / the error message can be corrected by ensuring that the names of all IDs are the same.

You can also ensure that you can go about your business freely, so you must do the following:

Set the report mode for this error to no report on the error reporting tab or the project options dialog box. You can find this at project -> project options