Some apps behave up when a new software update is loaded because they aren't ready for the changes.
Background-running applications are among the first to suffer negative consequences as a result of recent platform changes. If you were using
WhatsApp and didn't close the app before upgrading iOS, cached files for WhatsApp or the program itself may have crashed, causing the app to glitch. Clearing WhatsApp, or any other background programs for that matter, is advised as a remedy. Here's how to do it:
1. To open the app switcher, press the Home button twice fast. It will show you previews of the applications you've recently used but haven't closed.
2. To clear the WhatsApp preview, swipe up.
3. Simply swipe upon each of the remaining app previews to remove additional background apps.
After you've cleared all background apps, try relaunching WhatsApp to see whether it works. if it is already loading and working properly. If not, then continue to
troubleshoot.
