Today is iOS 9 update day but many users who fired up their Software Update function on their iPhones, iPads and iPod Touches were faced with an inability to update their devices due to a 'Software Update Failed error - Error Occurred downloading iOS 9' error. This seems to be an issue with OTA (Over the Air) updates.
I tried numerous times to enable the Software Update on my iPhone 6 Plus but couldn't resolve the issue until I plugged in my device to my MacBook which seemed to be working, albeit slowly as it is backing everything up. Pressing software update on my iPhone 5c doesn't even bring up the option. Stay tuned for developments.
iOS 9 seems to be working as a Software Update download. The file takes around 25 minutes to download via WiFi.