Cannot access script base class 'org.gradle.kotlin.dsl.KotlinBuildScript'

Issue

When I create an empty project with Gradle Kotlin DSL, even without any modifications, it would prompt Cannot access script base class 'org.gradle.kotlin.dsl.KotlinBuildScript'. Check your module classpath for missing or conflicting dependencies The project can run, but the syntax highlighting and autocompletion for build.gradle.kts don't work.

What I've tried

• https://github.com/gradle/kotlin-dsl-samples/issues/1308
  • Changing gradle executable to gradle-kotlin-dsl-5.2-20190122225509+0000-all.zip
• https://youtrack.jetbrains.com/issue/KT-38296
  • Remove empty SDKs in Project structure dialog
  • Invalidate caches and restart
• Reinstalling Java 11 brew install java11
• Switching to official oracle JDK 15 ​brew install oracle-jdk
• https://youtrack.jetbrains.com/issue/KT-41141
  • Re-adding SDKs in the SDK menu
  • Adding /Kotlin/kotlinc/lib to Kotlin SDK's classpath
• http://youtrack.jetbrains.com/issue/IDEA-245027
  • Deleting the cache folder manually

System

IntelliJ IDEA 2020.3.1 (Ultimate Edition)
Build #IU-203.6682.168, built on December 29, 2020
Licensed to Hykilpikonna Gui
Subscription is active until November 28, 2021.
For educational use only.
Runtime version: 11.0.9.1+11-b1145.63 x86_64
VM: OpenJDK 64-Bit Server VM by JetBrains s.r.o.
macOS 10.15.7
GC: ParNew, ConcurrentMarkSweep
Memory: 1998M
Cores: 6
Registry: debugger.watches.in.variables=false, js.debugger.webconsole=false
Non-Bundled Plugins: CMD Support, Rider UI Theme Pack, Statistic, com.alayouni.ansiHighlight, com.intellij.ideolog, net.vektah.codeglance, String Manipulation, com.alibaba.p3c.smartfox, wu.seal.tool.jsontokotlin, com.demonwav.minecraft-dev, lermitage.intellij.extra.icons, com.github.masahirosuzuka.PhoneGapIntelliJPlugin, Dart, io.flutter, deno, org.jetbrains.kotlin, com.cybrosis.catdea, siosio.kodkod, izhangzhihao.rainbow.brackets, org.jetbrains.plugins.ruby, Pythonid, org.jetbrains.plugins.vue, tv.twelvetone.intellij.plugins.intellivue, ru.meanmail.plugin.requirements

Solution

Answer credit to @AlexeyBelkov - Answered here: https://youtrack.jetbrains.com/issue/KTIJ-893

The syntax highlighting feature worked after:

1. Delete ~/.gradle/caches
2. Delete ~/Library/Application\ Support/Library/JetBrains/IntelliJIdea2020.3 (or ~/.cache/JetBrains/IntelliJIdea2020.3 for ubuntu/linux users)
3. Delete <project dir>/.gradle
4. Delete <project dir>/.idea
5. Start IDEA and reimport the project.

Answered By - Hykilpikonna