I was trying out fsstudio and I couldn't get it to find my SPAE.PA file. I ended up hardcoding a full path to it as the only place it was checking was c:/Users/username/.local/ paths and .local doesn't seem to be a valid directory in windows.
commented out the path builder line and hardcoded to location I placed SPAE file in data-source-dos.cc
//std::string file_path = path + '/' + file_name;
std::string file_path = "C:/SPAE.PA";
I now see game graphics in the FS Studio