Photos showing as blank, grey squares on iPhone 6S
I received my iPhone 6S this week and followed all the guidance for upgrading from my old 5.
All seemed to go well and the new phone was up and running quickly. However, the majority of my photos that were on the iPhone 5 are not visible on the new 6S. 'All Photos' is indicating that here are 601 photos but I can only see 28, all taken in the last week. All the other photos are showing as blank, grey squares.
I have searched the web and can't find any solution to this problem.
Can anyone here provide any advice, please?
iPhone 6s, iOS 9.0.2