CoroutineContext version up issue

I was using Kotlin version 1.2.41 and I upgraded Kotlin version 1.2.41 to 1.3.21. Then, I got compile Error.

$ ‘runBlocking(CoroutineContext = ..., suspend CoroutineScope.() -> T): T’ is only available since Kotlin 1.3 and cannot be used in Kotlin 1.2

Here is original code

plugins {
    id "org.jetbrains.kotlin.jvm" version "$kotlinVersion"
    id "org.jetbrains.kotlin.plugin.spring" version "$kotlinVersion"
    id "nebula.kotin" version "1.2.41"
}

compileKotlin {
    kotlinOptions {
        apiVersion = "1.2"
        languageVersion = "1.2"
    }
}

org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlinVersion
org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlinVersion
org.jetbrains.kotlin:kotlin-stdlib:$kotlinVersion
org.jetbrains.kotlin:kotlin-reflect:$kotlinVersion


org.jetbrains.kotlinx:kotlinx-coroutines-core:$kotlinStdlib
org.jetbrains.kotlinx:kotlinx-coroutines-jdk8:$kotlinStdlib
org.jetbrains.kotlinx:kotlinx-coroutines-nio:$kotlinStdlib
org.jetbrains.kotlinx:kotlinx-coroutines-rx2:$kotlinStdlib
org.jetbrains.kotlinx:kotlinx-coroutines-reactor:$kotlinStdlib

and I changed these variables from 

kotlinStdlib = 1.2.31
kotlinVersion = 1.2.41
kotlinxCoroutines = 0.22.5

to 

kotlinStdlib = 1.3.21
kotlinVersion = 1.3.21
kotlinxCoroutines = 1.2.2

But I get error on kotlinx.coroutines.runBlocking function as below

$ ‘runBlocking(CoroutineContext = ..., suspend CoroutineScope.() -> T): T’ is only available since Kotlin 1.3 and cannot be used in Kotlin 1.2

I solved problem with below steps.

First, I searched google but there was so old reference come up : https://stackoverflow.com/questions/53030756/launch-is-only-available-since-kotlin-1-3-and-cannot-be-used-in-kotlin-1-2

I followed above reference(try this first since it might possible to fix your case):  checking IDEA Setting(Kotlin Compiler version, Kotlin plugin version) 

But it doesn’t help for me.

Finally, I found that one of library(nebula.kotlin) is using kotlin which version is legacy(1.2.41) -> need to change 1.3.21

And also apiVersion, languageVersion in kotlinOptions in Build.gradle file, is also pointing Kotlin version 1.2.x. -> need to 1.3 or remove

and then finally fixed, go to bed