Question: How is it possible that I get this message? It does not make any sense.
I'm using `com.squareup.retrofit2:retrofit:2.9.0`

```
     Caused by: java.lang.IllegalStateException: Expected Android API level 21+ but was 30
    at okhttp3.internal.platform.AndroidPlatform$Companion.buildIfSupported(AndroidPlatform.kt:370)
    at okhttp3.internal.platform.Platform$Companion.findPlatform(Platform.kt:204)
    at okhttp3.internal.platform.Platform$Companion.access$findPlatform(Platform.kt:178)
    2020-09-16 12:37:07.645 6480-6480/lv.ltt.gasogmp.dev_v3 E/AndroidRuntime:     at 
    okhttp3.internal.platform.Platform.<clinit>(Platform.kt:179)

```

Answer: 
Add an explicit dependency on OkHttp 4.9.0. Or whatever is newest at the time you read this.

This bug is embarrassing but it's been fixed for so long that you shouldn’t be encountering it in new code.
Add `implementation 'com.squareup.okhttp3:okhttp:4.9.2'` inside `android\app\build.gradle`

```
dependencies {
    ........
    implementation 'com.google.code.gson:gson:2.8.6'
    implementation 'com.android.support:multidex:1.0.3'   
    implementation 'com.squareup.okhttp3:okhttp:4.9.2' 
    ..........
}

```