Unable to find method 'org.gradle.api.tasks.SourceSetOutput.getClassesDir()Ljava/io/File;

[Lance (uklance)]

Could not get unknown property 'classesDir' for main classes

The problem is that either your build.gradle or a plugin referenced in your build.gradle is using a method that was deprecated in Gradle 4 and removed in Gradle 5. If its your build.gradle then you need to change it from using SourceSetOutput.getClassesDir() to SourceSetOutput.getClassesDirs() If its a plugin, then possibly you are on an old version and updating to a newer version will fix. If not you might need to contact the plugin author to get a fix, or perhaps submit a pull request You c…