Hi

I have created an interactive book in which I have few interactive videos and one regular video. I have been able to save the file so far. But suddenly, I get an error that the file cannot be saved. I tried multiple times, with some break in between. But no luck. I closed the file and see that the file size is good enough, which probably indicates that the file has the content I added. But when I tried to open it, it says unable to open. Is there a way to open or retrieve somehow? Too much of effort will go waste if I cannot.

Please help.