how to use the .log files?

I just started testing this emulator, and I have a basic question.  I see that there is a forum section called "playable", and every thread there refers to a specific game with an attached zip file.  Upon opening this, is see that it appears to be a configuration file, only it is titled (gamename).log.  I tried to place this in the folder where the current config file for the game that I am testing is and renaming it to match the old file already in there (I renamed the old one to preserve it).  However, when I started the game, I noticed on the printout that it failed to load the configuration file. 

I probably missed the answer somewhere, but how am I supposed to use these .log files?  Thanks in advance!