People of digital domain can live without oxygen for a few minutes but if WhatsApp gets removed from their smartphones, they will turn neurotic. And it's really annoying, if WhatsApp crashes every time. There is no particular reason for the issue, but there are possible fixes for the problem.
Earlier, the issue was faced in iOS 8 on iPhone and now, many users are facing WhatsApp crashing issue on iOS 9 enabled iPhone as well. As always, we have some fixes that have proved to be working for few fellows. I am not sure if they will work for you, but it's better to give them as try. So just head south and try the fixes we have mentioned.
How to Fix WhatsApp Crashing Issue in iOS 9:
We will try to keep things simple in the beginning and keep the painful processes for later. So first of all, delete the WhatsApp app from your iPhone/iPad and then install it again from the App Store. I know you guys are smart and should have already done this basic troubleshooting, but even then just give it a try one more time. Now check if WhatsApp is back to life, if it isn't, keep reading below.
Reinstall WhatsApp without restoring
You must have already followed the first fix and I am sorry, you'll have to do it again. This time, do not restore from the backup when WhatsApp asks you. Instead, set up WhatsApp as new. This is surely a pain, but I already warned you about it earlier. After WhatsApp finishes the initializing process, check if you are able to start a conversation without the app getting crashed. If not, then start worrying a bit, as things will get a little nasty from here on.
Facebook contacts sync could be the culprit
If you have recently updated the Facebook app to the latest version, and also you have enabled contact sync between Facebook and iPhone, then this could be the issue. That's because WhatsApp resizes the images in the Contacts app. As the images are derived from Facebook, you should consider disabling contacts sync with Facebook. To do so, go to the Settings app on iPhone → Facebook → toggle off “Contacts”.
Delete contact picture
If you are still reading, then it means that simply disabling contacts sync with Facebook hasn't helped you. Let's take it a step further, delete images from all the contacts and check if WhatsApp is revived or not. In order to do so, open Contacts → tap on a contact with image → Edit → tap Edit below the image → Delete Photo. It's a bit of a tedious process, but that should work.
Turn off WhatsApp iCloud Backups
One of the culprits could be the iCloud backups. There are a number of factors which might result in a failed backup, and it is next to impossible to determine each and everyone. The easiest way is to disable this option and use WhatsApp peacefully. You'll just need to open WhatsApp → Settings → Chats → Chat Backup → Auto Backup → Turn it Off.
Factory reset your iPhone
This is the last and the final option left. Before proceeding with the reset, make sure you make a fresh backup with iTunes. Then go to Settings → General → Reset → Erase all Content and Settings. After your iPhone has been reset, restore it using iTunes. But make sure you don't restore the apps. It's better to make a fresh download of WhatsApp from App Store.
That's all friends; this is all we have got to offer you for WhatsApp crash issue. If you have any other working fix that might help the fellow iPhone or iPad users, then don't forget to mention them in the comments.