I do not have the special knowledge to answer you, but I suspect that if you can reply back here with more context, others will be more prepared to assist you.
Specifically, what is broken when you say "the text is broken"?
Are you using LInux, Mac? What OS if Linux?
Can you give people here an idea of what your book is? Small, large?
Just a quick note - your image shows you using the "Story Editor" and if you are following some of the advice in the wiki, that is the tool to use. My experience with the story editor has been that it does not do everything it is supposed to as well as it is supposed to. This forum and some of its contributors are an excellent resource on where to use the Story Editor and where it may actually get in your way. My own experience is that I will only use it where I must - almost never. I hope more knowledgeable people will offer more expert opinions, but for me, I work in the text frame almost exclusively, and find it faster and less frustrating.
But, I may be speaking on a topic that has nothing to do with your issue. Fill us in on what is not working for you?