parsing config file problem

Hello list, I have a nanobts1800 and installed openbsc on Debian yesterday (from git). After building the project and configured the bts on the network, I executed bsc_hack with -c openbsc.cfg.nanobts. But it failed to execute with the following error: <0005> bsc_init.c:860 Failed to parse the config file: 'openbsc.cfg.nanobts' I haven't modified the config file, I haven't modified anything at all in openbsc. Any idea? Thanks.