Though bus name doesn't have the brackets ,DRC output shows
But,It is connected properly between two blocks.
The bus name implies that it has been set up using Bus Contents (Setup - Settings - Project - Bus Contents) as the bus name does not contain any range information ( like BUS[7:0]) So the list of the bus contents entry is what is being flagged for the odd number of brackets. What is in the bus contents file for this bus?
Retrieving data ...