General Description: When synthesizing an HDL macro to be placed on a Foundation schematic, the following error message may occur:
"CONV: line X Wrong number of fields BUS"
where X refers to an actual line number.
Solution
This may occur when a BUS has been declared as a port for this macro and then is entirely unused in the HDL code. FPGA Express has trimmed the logic for the bus but the declaration still exists in the XSF file (which is used to create the schematic symbol).
Open the <macro_name>.XSF file (located in the project directory) and examine the line number refered to in the error to determine the bus signal that has been removed. Remove this port declaration in your HDL source and re-synthesize.