The Facebook app isn't working on my iPhone

Apple released a Rapid Security Response on Monday that proved to be buggy. They pulled it almost immediately because it made it caused problems with accessing some web sites including Facebook. See:

If you applied Rapid Security Response iOS 16.5.1 (a), iPadOS 16.5.1 (a), or macOS Ventura 13.4.1 (a) - Apple Support

and this Arstechnica article:

https://arstechnica.com/security/2023/07/apple-releases-quickly-pulls-rapid-security-response-update-for-0-day-webkit-bug/

Remove the bad file using instruction in that article. The repalced, version (c) was relased Thursdays and I have hed no issues with it.

Hello 3zo3zo!

If you’re having issues with third party apps, please contact the developer/s of them for further assistance.

In this case, try following the on-screen instructions.

I hope this is helpful. Good Luck!

I am having the same issue, did you solve it??

Have you contacted Facebook ?

I have contacted Facebook, they told me to contact ios developers cause they have a lot users facing the same issue since last software update.

change wifi server and connection error.check facebook update.