Receiving domain error code 100 when trying to login to Facebook, ive

Hello, Andrewk444. Thank you for visiting the Apple Support Communities. We understand that you are noticing an error when you attempt to sign in with your Facebook account. We know that staying online and connected is important and we’re happy to research the cause of this issue together. 

From the screenshot you sent, we can see that the error message may be network related. There are several steps that we’d suggest starting with for an issue like this. 

To start, we should be sure that your version of iOS and your app are fully updated. The following Apple Support articles explain how you can install any available updates: 

Update your iPhone, iPad, or iPod touch - Apple Support

How to manually update apps on your Apple device - Apple Support

For connection issues like this, we also suggest that you make sure the date and time on your device are set correctly for your time zone. You can view the date and time settings for your device in the Settings app. Open Settings > General > Date & Time to manage these settings. 

If you still can’t connect after this, we’d like to find out more. To continue, can you tell us if you notice any similar issues when connecting with other apps at this time? 

Does the same message appear when you sign in while connected to another Wi-Fi network, or with cellular data? 

We hope the information above helps you find a solution and we look forward to your reply.

Cheers!