diff --git a/idea/idea-gradle/src/org/jetbrains/kotlin/idea/configuration/KotlinWithGradleConfigurator.kt b/idea/idea-gradle/src/org/jetbrains/kotlin/idea/configuration/KotlinWithGradleConfigurator.kt
index 13fb0f32d8a..1fde5c7dac2 100644
--- a/idea/idea-gradle/src/org/jetbrains/kotlin/idea/configuration/KotlinWithGradleConfigurator.kt
+++ b/idea/idea-gradle/src/org/jetbrains/kotlin/idea/configuration/KotlinWithGradleConfigurator.kt
@@ -151,11 +151,11 @@ abstract class KotlinWithGradleConfigurator : KotlinProjectConfigurator {
         val sdk = ModuleUtil.findModuleForPsiElement(file)?.let { ModuleRootManager.getInstance(it).sdk }
         val jvmTarget = getJvmTarget(sdk, version)
         return getManipulator(file).configureModuleBuildScript(
-                kotlinPluginName,
-                getKotlinPluginExpression(file.isKtDsl()),
-                getStdlibArtifactName(sdk, version),
-                version,
-                jvmTarget
+            kotlinPluginName,
+            getKotlinPluginExpression(file.isKtDsl()),
+            getStdlibArtifactName(sdk, version),
+            version,
+            jvmTarget
         )
     }
 
@@ -261,7 +261,7 @@ abstract class KotlinWithGradleConfigurator : KotlinProjectConfigurator {
         fun getManipulator(file: PsiFile, preferNewSyntax: Boolean = true): GradleBuildScriptManipulator<*> = when (file) {
             is KtFile -> KotlinBuildScriptManipulator(file, preferNewSyntax)
             is GroovyFile -> GroovyBuildScriptManipulator(file, preferNewSyntax)
-            else -> error("Unknown build script file type!")
+            else -> error("Unknown build script file type (${file::class.qualifiedName})!")
         }
 
         val GROUP_ID = "org.jetbrains.kotlin"
diff --git a/idea/idea-gradle/src/org/jetbrains/kotlin/idea/configuration/KotlinWithGradleConfigurator.kt.as31 b/idea/idea-gradle/src/org/jetbrains/kotlin/idea/configuration/KotlinWithGradleConfigurator.kt.as31
index 2dd604e45ed..16cbd7d32af 100644
--- a/idea/idea-gradle/src/org/jetbrains/kotlin/idea/configuration/KotlinWithGradleConfigurator.kt.as31
+++ b/idea/idea-gradle/src/org/jetbrains/kotlin/idea/configuration/KotlinWithGradleConfigurator.kt.as31
@@ -266,7 +266,7 @@ abstract class KotlinWithGradleConfigurator : KotlinProjectConfigurator {
         fun getManipulator(file: PsiFile, preferNewSyntax: Boolean = true): GradleBuildScriptManipulator<*> = when (file) {
             is KtFile -> KotlinBuildScriptManipulator(file, preferNewSyntax)
             is GroovyFile -> GroovyBuildScriptManipulator(file, preferNewSyntax)
-            else -> error("Unknown build script file type!")
+            else -> error("Unknown build script file type (${file::class.qualifiedName})!")
         }
 
         val GROUP_ID = "org.jetbrains.kotlin"
diff --git a/idea/idea-gradle/src/org/jetbrains/kotlin/idea/configuration/KotlinWithGradleConfigurator.kt.as32 b/idea/idea-gradle/src/org/jetbrains/kotlin/idea/configuration/KotlinWithGradleConfigurator.kt.as32
index 2dd604e45ed..16cbd7d32af 100644
--- a/idea/idea-gradle/src/org/jetbrains/kotlin/idea/configuration/KotlinWithGradleConfigurator.kt.as32
+++ b/idea/idea-gradle/src/org/jetbrains/kotlin/idea/configuration/KotlinWithGradleConfigurator.kt.as32
@@ -266,7 +266,7 @@ abstract class KotlinWithGradleConfigurator : KotlinProjectConfigurator {
         fun getManipulator(file: PsiFile, preferNewSyntax: Boolean = true): GradleBuildScriptManipulator<*> = when (file) {
             is KtFile -> KotlinBuildScriptManipulator(file, preferNewSyntax)
             is GroovyFile -> GroovyBuildScriptManipulator(file, preferNewSyntax)
-            else -> error("Unknown build script file type!")
+            else -> error("Unknown build script file type (${file::class.qualifiedName})!")
         }
 
         val GROUP_ID = "org.jetbrains.kotlin"