I have the same problem transferring photos from iPhone5 to windows vista. It used to work great. After updating to ios8 .3 I now have to manually enter the device address. It discovers the device but when it goes to find photos, it says Error - Authorization. There is a problem communicating with the device. Privacy settings are set ok. I restarted the iPhone. I have the iCloud Photo Library off, my photo stream on. I am on home wifi and tried when nobody else was on. Is it a problem with the wifi?
Here's an update. The problem is intermittent, so it probably has to do with my internet service.