How to Fix iCloud Backup Not Working in iOS 9

Almost all iOS users around the globe have updated their devices to the latest iOS 9. After the update, many users encountered issues regarding iCloud backup not working on iPhone 6. This is another bug of iOS 9 and an issue to be resolved. But there are also possible solutions for the iCloud back up problem.
Fixing iCloud Backup Not Working on iPhone 6 iOS 9.0
It could be possible that the bug is in the phone, so just try to sign out and sign in again. If this does not solve the issue, follow this step by step instructions.
Solution 1: Wifi Reset Network Settings on iPhone 6
Step 1: From home screen, go to Settings App and choose General.
Step 2: Scroll down and tap on Reset.
Step 3: Select Reset Network Settings.
Step 4: Enter your passcode to confirm. This should solve your problem regarding iCloud backup, if it does not work, try other solutions.
Could not backup Solution 2: Disable automatic backups
Even if you have enough storage in iCloud, you still get error when backing up because of the size of apps you are backing up. Disable some of the apps that you do not need to delete iCloud storage backup. To do this:
Step 1: On Settings app, choose iCloud.
Step 2: From iCloud, select Storage and choose Manage.
Step 3: You will see under Documents & Data the list of apps and their corresponding sizes.
Step 4: Go back to iCloud and select iCloud drive so you can turn off the apps that are consuming a lot of space and you do not need much.
Step 5: After disabling some apps, go back to iCloud settings and choose Photos.
Step 6: Switch off the 3 options, iCloud Photo library, My Photo Stream, and iCloud Photo Sharing.
Solution 3: Delete Older iCloud Backups
Step 1: Go to Settings and choose iCloud.
Step 2: Tap Manage Storage.
Step 3: You will see the lists of your back up. Choose and delete those which you do not really need by tapping on the Delete Backup button.
This solution can work especially when you also get Not Enough Storage problems. Now check if you can already use your iCloud.
Solution 4: Update Your Device to the Latest iOS 9.3 Version
Apple released updates for fixing bugs which also includes your issues. Check for new updates on Settings, then General. Click on Software Update and if it shows available nerwer versions, tap Download and Install. Just wait for your device to finish installing, then check if iCloud already works.
If you did all those, and still couldn’t fix this problem. You might want to check did you set-up iCloud correctly.