new ios 11 update erased keynote files from my iphone

Hi,

I updated to the newest version of iOs on my iphone a few nights ago. When I went to use a previous Keynote presentation while teaching yesterday, it would not let me click my file. At one point it said "This file does not exist." There was never a problem with this previously. I have tried looking for it through iCloud but am getting nothing. I had put everything on iCloud before, but now in the general settings, I had to click iCloud on the menu.

The icons for my previous presentations are still on my phone, with the date last used and the amount of space they each take up. However, they are all unavailable to me at this time. I need these to teach a few classes that are behind schedule and did not see this information yet.

Is there a way to recover these files that should be available on my iPhone?

Thanks.