Go to Settings > General > iPhone Storage, and see if there's any storage space available. You can also consider deleting some data or upgrading your storage plan.
If you're experiencing slow performance or crashes, try using Facebook Lite. It's a lighter version of the app that's designed for slower networks and older devices. facebook old version for ios 1255 install
Share this post with friends who might still be using older iOS devices, and let's help each other out! Go to Settings > General > iPhone Storage,
Make sure you're running the latest version of Facebook that's compatible with your iOS device. You can check for updates in the App Store. It's a lighter version of the app that's
Clearing cache and cookies can help resolve issues with the app. Go to Settings > Safari > Clear History and Website Data.
"Tips for Using Facebook on Older iOS Devices"