Cannot run the sample command

[nipunagarwala]

I am running the following command, given in the README:
./ramulator configs/DD43-config.cfg --mode=dram dram.trace

But I get the following error:
ramulator: src/StatType.h:97: void Stats::StatList::output(std::string): Assertion `false && "!stat_output.good()"' failed.

Would you know how to get around this?
Thank you!