Facebook iOS Log-in no longer works in 2018.3 / 2018.4 / 2019.1

Hi,

I am trying to update my project from 2018.1.6f1 to 2018.4.0f1 LTS.

I am experiencing an issue where logging in to Facebook on iOS devices no longer works, but it does work on Android and Kindle.

I have tried a lot of different things to figure out what goes wrong. Note that there has never been any log-in issues with this setup through many many Unity versions. We are talking from 4.x, 5.x and up.

To narrow in what change in Unity could affect this, I have tried these versions out:

• 2018.1.6f1: WORKS
• 2018.1.9f2: WORKS
• 2018.2.21f1: WORKS
• 2018.3.0f2: FAIL
• 2018.3.14f1: FAIL
• 2018.4.0f1: FAIL
• 2019.1.3f1: FAIL

So something must be inherently different in 2018.3 - does anybody have any idea what that could be?

I know you will be saying to look at the logs, and I have done that, but Facebook SDK is notoriously bad at saying what is wrong. The error is essentially a statechange to 'FBSessionStateClosedLoginFailed' when trying to log in, with a response of 'CLOSED_LOGIN_FAILED'. Google yields few results that makes sense for an iOS setup. I have verified that the bundle identifier is correct.

 

Issue was fixed by overwriting the openURL app delegate method of Unity, for the Facebook plugin, rather than the handleOpenURL, which is deprecated. Presumably something changed in Unity 2018.3 which made handleOpenURL obsolete, yet Xcode will compile it.

https://developer.apple.com/documen...iondelegate/1622964-application?language=objc
https://developer.apple.com/documen...iondelegate/1623112-application?language=objc