import org.jetbrains.yaml.YAMLFileTypeLoader failes

I am new to gradle and need some help

I am trying to build a custom plugin , if I use intelliJ version "2017.1.6"  it works fine , but it doesn work with 2021.1 (version) . When using 2017.1.6 I use Java version 1.8 while with 2021.1 I tried using Java 11 and Java 16 ...but both gives the same error 

(error: cannot find symbol  org.jetbrains.yaml.YAMLFileTypeLoader )

I am attaching snippets from  build.gradle

plugins {
    id 'org.jetbrains.intellij' version '0.7.2'
}

intellij {
    version '2021.1.1'
    plugins =['yaml']
    downloadSources = false
    updateSinceUntilBuild = false
}

sourceCompatibility = 11
targetCompatibility = 11

Plugins .xml already has this dependency 

<depends>org.jetbrains.plugins.yaml</depends>