When I implement or synthesize a schematic design, the following message occurs:
"ERROR:DesignEntry:215 - Net "<net_name>(bit#)" is an illegal name, because there is no corresponding bit bus for this bit bus member."
This is a valid error, and it occurs when a net name refers to a bit bus when there is not a corresponding bit bus.
To remove this message, rename the net or create a proper bus that encompasses the bit bus member.
Four nets named a(0), a(1), a(2), and a(3) generate four instances of this error if there is not a bus with the base name of "a" with indexes from 0 to at least 3.
NOTE: If the bus exists but is part of a larger, concatenated bus (e.g., a(3:0),b(1:0),gnd), the schematic editor does not recognize the bus and still generates the error.
To fix these errors, draw a net and name it a(3:0).