I tried to create a 300ppi "Multiply" layer as set out here http://indesignsecrets.com/raise-image-resolution-directly-in-indesign.php Part of the advice was to reorder content into layers of 'images' and 'text'. Seeing as the layers only show what is on the current page(s) I assumed if you were deleting an empty layer you were only deleting it from the current page, so I have deleted some layers that contained text on other pages in my magazine.
[Note: When I realised, I 'reverted' to the saved version but I was saving regularly which paradoxically means that reverting was the worst thing I could have done as it took me back to a position where I already had some layers missing. If I had simply 'Undone' everything I would probably have been fine.]
I thought I had lost all the text because all of my text boxes are blank (white) but it looks like the text is still there. They are all overset and if I select a frame and select 'all' I can copy and paste the text into (say) Notepad but I just can't work out how to recover them back into a layer/their boxes.
I can probably recreate the magazine in this roundabout way but I don't have the experience to work out what I have done. Please can someone work out what I have done and possibly a way to fix it? Many thanks. I have tried turning the resolution layer off to no effect but not deleting it yet.
I deleted the jpg files from the Master pages and Hey Presto! the text has come back. Panic over.