Had a strange one today, wanted to work on a spreadsheet on my iPad, but Numbers or Pages would not load, it was just a white blank page.
When I tried to click on the Files app, that would just flash up and disappear as well. It seemed that any app that needed to connect to iCloud would not open, this included PDFPen.
I tried deleting and reinstalling, Files, Numbers and Pages, but still nothing. I also tried signing in and out of iCloud again still nothing. Worked fine on the laptop and on my phone, just not the iPad.
The only thing that fixed this was to upgrade to the latest iOS version. Afterward the app would open and I could use the apps again, really really annoying.
With Apple recent admission of slowing down phones, is this another "bug" they have introduced to get you to update to the latest iOS, I was only a couple of minor revisions behind.
I am always interested in your thoughts so if you have any comments or feedback then please feel free to add any comments, or you can mail me here.