I created a bdf schematic with a single 74191 from the maxplus2 library., and compiled without error. Then I converted the file to VHDL and tried to compile it. Result has 2 syntax errors. Bug in Quartus (Win7 64-bit) converter?
In vhdl the entity names must begin with a letter like "ic_74191". Probably schematic editor accepted a numeric name for your top entity but a vhdl source don't. Try to change the name of the bdf file and the convert it to vhdl.
