Section in Test disappeared

Hi,

Test was created which then, at the request of the client, required a section adding within it, I tried this on a test test and all was fine, however when I added a section to the test and moved the question pages into it, it disappeared. Anyone have any experience of this and why it may have happened? Have lost work and am concerned it will happen again if I'm missing something when adding a section that is causing it to lose the information?