The cache file contains the articles that the account has already posted so it doesn't repost them on the next fetch. So when you first start it up, obviously no cache file exists because no articles have been posted yet. After the cache is initialized, it should fetch articles and post them. It should start making a bunch of posts after it initializes but I can't remember if it may wait for the fetch interval. If nothing posted after, just stop it and start it again and it should go.