I asked for a prognosis on the medium term outlook of my life situation (financial etc) and got hexagram 13 with every line changing except 1 (13: 2,3,4,5,6).How do I interpret such a reading?

First what do you mean by, 'medium term' ? And second, which hexagram is it changing to? That way we don't have to look it up. And finally, please read the sticky posted at the top of this forum about how to get the most from sharing a reading. In summary it suggests:

Share...some background and context for your reading - enough for people to understand what it's about.

the question you asked, word for word.

the answer Yi gave. (Our favourite format is like this: '27.2.5 to 61'.)

your own feelings and thoughts about the answer.

So, a bit more about what you asked - and maybe why, and some about what your take on it is, or what you think it means ....