iPhone seems to have to "download" all my recent photos, but iCloud is turned off I normally let my recently taken camera pictures sync with Dropbox. Since the sync wasn't happening, I started to investigate. It seems that my recent pictures aren't stored on my iPhone. When I try to open a picture, then do edit -> enhance. It says: "downloading picture", then it gets stuck at 25%. What happened? If the pictures are not on my phone itself, Dropbox can't sync them.  

My iCloud photo library and My Photo stream has been turned off for ages.

I have a linux computer, and since Apple doesn't support linux, I need a way to copy my recently shot pictures to my pc. This has worked fine for years. Now I can't even edit my recent pictures on my phone. Strange... 

I went to icloud.com and checked pictures, but it gives me instructions on how to activate icloud. 

When I check my memory usage of the phone itself, it lists my music etc, but nothing for pictures. What happened? 

I recently updated my iPhone to 9.3.1 (don't know if that's relevant)
A second reboot fixed the problem...