For anyone still experiencing this issue, specifically when importing from an iOS device to Windows 10, go into your iPhone's settings;
Settings>Photos>Transfer to MAC or PC (At the bottom)
Make sure this setting is on 'Keep Originals'.
I was having an issue where the photos app would only import 1-3 photos successfully and then "something went wrong" would appear. Apparently there is a conflict between what the iOS device is trying to export the photo as when it's converting it and what the Windows 10 Photos app is expecting to import.
Hope this Helps!