It means bmake file is not able to find mdlexmpl.mki.
If you use MicroStation Development Shell, everything should be set automatically, but a threat of some problem with not-standard environment or installation always exist.
You can try to start the compilation using bmake -v -a basic > log.txt and try to find in the output, when mdlexmpl.mki is called and what path is expected.
Regards,
Jan