I've solved my problem so here is what I did. I created a droplet in compressor and was able to drop hundreds of files into the droplet to be converted. It was simple in my case. All source files were of one type. And the output files, the setting and the destination were the same. So the droplet was a simple one (I understand they can be complex).
Hope this helps others with the Compressor quit problem when loading more than 15 or 20 source files.