Steps to reproduce:
1. Download the project "938287 repro.zip"
2. Build the test scene to iOS
3. Open the build with XCode
4. (This step is required because of an existing issue, Case 938208) Navigate to Data/Managed/mono and rename folder "2.0" to "4.0"
5. Deploy to an iOS device
6. Observe the console

Expected result: no errors after Debug.Log("query");, text on screen is changed
Actual results:
iOS / Android 2017.1: ArgumentNullException: Value cannot be null.
iOS / Android 2017.2: IL2CPP error when building
iOS 2017.3: NotSupportedException: Could not find TLS Provider: `Mono.AppleTls.AppleTlsProvider'.
Android 2017.3: "Unable to find libc" (CRASH)

Tested on: iPhone 6 (iOS 10.3.3), LG Nexus 5X (Android 7.1.2)
Reproduced on: 2017.1.0f3, 2017.1.0p2, 2017.3.0a2
Unable to reproduce on: 2017.2.0b3, 2017.2.0b6 (IL2CPP errors)

Fixed in:2017.3.0b1