Unable to open Facebook on my iPhone 15 Pro Max

First try a forced restart, if that doesn't work reinstall the app. If that doesn't work contact the app developer for help with their software.

Try a forced restart.

• Press and quickly release the volume up button

• Press and quickly release the volume down button

• Press and hold the side button.

• When the Apple logo appears, release the button.

Force restart iPhone - Apple Support (IN) Force restart iPhone - Apple Support (IN)

Contact Meta for help with their software.

Here is a link to their help page.

https://facebook.com/help/?<https://m.facebook.com/help/?r>

Have you tried updating to the latest iOS or version of Facebook?

What did Facebook say about it when you contacted them?