diff --git a/core/src/main/resources/error/error-classes.json b/core/src/main/resources/error/error-classes.json
index 2e32482328a7e..2d16ec50a6612 100644
--- a/core/src/main/resources/error/error-classes.json
+++ b/core/src/main/resources/error/error-classes.json
@@ -184,6 +184,17 @@
   "UNSUPPORTED_OPERATION" : {
     "message" : [ "The operation is not supported: <operation>" ]
   },
+  "UNSUPPORTED_SAVE_MODE" : {
+    "message" : [ "The save mode <saveMode> is not supported for: " ],
+    "subClass" : {
+      "EXISTENT_PATH" : {
+        "message" : [ "an existent path." ]
+      },
+      "NON_EXISTENT_PATH" : {
+        "message" : [ "a non-existent path." ]
+      }
+    }
+  },
   "WRITING_JOB_ABORTED" : {
     "message" : [ "Writing job aborted" ],
     "sqlState" : "40000"
diff --git a/core/src/main/scala/org/apache/spark/ErrorInfo.scala b/core/src/main/scala/org/apache/spark/ErrorInfo.scala
index 99e081ebb45ea..fa2e1034692ac 100644
--- a/core/src/main/scala/org/apache/spark/ErrorInfo.scala
+++ b/core/src/main/scala/org/apache/spark/ErrorInfo.scala
@@ -28,14 +28,30 @@ import com.fasterxml.jackson.module.scala.DefaultScalaModule
 
 import org.apache.spark.util.Utils
 
+/**
+ * Information associated with an error subclass.
+ *
+ * @param message C-style message format compatible with printf.
+ *                The error message is constructed by concatenating the lines with newlines.
+ */
+private[spark] case class ErrorSubInfo(message: Seq[String]) {
+  // For compatibility with multi-line error messages
+  @JsonIgnore
+  val messageFormat: String = message.mkString("\n")
+}
+
 /**
  * Information associated with an error class.
  *
  * @param sqlState SQLSTATE associated with this class.
+ * @param subClass SubClass associated with this class.
  * @param message C-style message format compatible with printf.
  *                The error message is constructed by concatenating the lines with newlines.
  */
-private[spark] case class ErrorInfo(message: Seq[String], sqlState: Option[String]) {
+private[spark] case class ErrorInfo(
+    message: Seq[String],
+    subClass: Option[Map[String, ErrorSubInfo]],
+    sqlState: Option[String]) {
   // For compatibility with multi-line error messages
   @JsonIgnore
   val messageFormat: String = message.mkString("\n")
@@ -61,13 +77,25 @@ private[spark] object SparkThrowableHelper {
       queryContext: String = ""): String = {
     val errorInfo = errorClassToInfoMap.getOrElse(errorClass,
       throw new IllegalArgumentException(s"Cannot find error class '$errorClass'"))
+    val (displayMessageParameters, displayFormat) = if (errorInfo.subClass.isDefined) {
+      val subClass = errorInfo.subClass.get
+      val subErrorClass = messageParameters.head
+      val errorSubInfo = subClass.getOrElse(subErrorClass,
+        throw new IllegalArgumentException(s"Cannot find sub error class '$subErrorClass'"))
+      val subMessageParameters = messageParameters.tail
+      (subMessageParameters, errorInfo.messageFormat + errorSubInfo.messageFormat)
+    } else {
+      (messageParameters, errorInfo.messageFormat)
+    }
+    val displayMessage = String.format(
+      displayFormat.replaceAll("<[a-zA-Z0-9_-]+>", "%s"),
+      displayMessageParameters : _*)
     val displayQueryContext = if (queryContext.isEmpty) {
       ""
     } else {
       s"\n$queryContext"
     }
-    String.format(errorInfo.messageFormat.replaceAll("<[a-zA-Z0-9_-]+>", "%s"),
-      messageParameters: _*) + displayQueryContext
+    s"$displayMessage$displayQueryContext"
   }
 
   def getSqlState(errorClass: String): String = {
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/errors/QueryExecutionErrors.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/errors/QueryExecutionErrors.scala
index 9e29acf04d2ef..6c6139d2ccc92 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/errors/QueryExecutionErrors.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/errors/QueryExecutionErrors.scala
@@ -652,8 +652,13 @@ private[sql] object QueryExecutionErrors extends QueryErrorsBase {
        """.stripMargin)
   }
 
-  def unsupportedSaveModeError(saveMode: String, pathExists: Boolean): Throwable = {
-    new IllegalStateException(s"unsupported save mode $saveMode ($pathExists)")
+  def saveModeUnsupportedError(saveMode: Any, pathExists: Boolean): Throwable = {
+    pathExists match {
+      case true => new SparkIllegalArgumentException(errorClass = "UNSUPPORTED_SAVE_MODE",
+        messageParameters = Array("EXISTENT_PATH", toSQLValue(saveMode, StringType)))
+      case _ => new SparkIllegalArgumentException(errorClass = "UNSUPPORTED_SAVE_MODE",
+        messageParameters = Array("NON_EXISTENT_PATH", toSQLValue(saveMode, StringType)))
+    }
   }
 
   def cannotClearOutputDirectoryError(staticPrefixPath: Path): Throwable = {
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/InsertIntoHadoopFsRelationCommand.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/InsertIntoHadoopFsRelationCommand.scala
index 74be483cd7c37..d773d4bd271b3 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/InsertIntoHadoopFsRelationCommand.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/InsertIntoHadoopFsRelationCommand.scala
@@ -133,7 +133,7 @@ case class InsertIntoHadoopFsRelationCommand(
         case (SaveMode.Ignore, exists) =>
           !exists
         case (s, exists) =>
-          throw QueryExecutionErrors.unsupportedSaveModeError(s.toString, exists)
+          throw QueryExecutionErrors.saveModeUnsupportedError(s, exists)
       }
     }
 
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/errors/QueryExecutionErrorsSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/errors/QueryExecutionErrorsSuite.scala
index e6ce1d7008039..73c5b12849a1d 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/errors/QueryExecutionErrorsSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/errors/QueryExecutionErrorsSuite.scala
@@ -17,14 +17,15 @@
 
 package org.apache.spark.sql.errors
 
-import org.apache.spark.{SparkArithmeticException, SparkException, SparkRuntimeException, SparkUnsupportedOperationException, SparkUpgradeException}
-import org.apache.spark.sql.{DataFrame, QueryTest}
+import org.apache.spark.{SparkArithmeticException, SparkException, SparkIllegalArgumentException, SparkRuntimeException, SparkUnsupportedOperationException, SparkUpgradeException}
+import org.apache.spark.sql.{DataFrame, QueryTest, SaveMode}
 import org.apache.spark.sql.execution.datasources.orc.OrcTest
 import org.apache.spark.sql.execution.datasources.parquet.ParquetTest
 import org.apache.spark.sql.functions.{lit, lower, struct, sum}
 import org.apache.spark.sql.internal.SQLConf
 import org.apache.spark.sql.internal.SQLConf.LegacyBehaviorPolicy.EXCEPTION
 import org.apache.spark.sql.test.SharedSparkSession
+import org.apache.spark.util.Utils
 
 class QueryExecutionErrorsSuite extends QueryTest
   with ParquetTest with OrcTest with SharedSparkSession {
@@ -265,4 +266,24 @@ class QueryExecutionErrorsSuite extends QueryTest
     assert(e.getMessage ===
       "Datetime operation overflow: add 1000000 YEAR to TIMESTAMP '2022-03-09 01:02:03'.")
   }
+
+  test("UNSUPPORTED_SAVE_MODE: unsupported null saveMode whether the path exists or not") {
+    withTempPath { path =>
+      val e1 = intercept[SparkIllegalArgumentException] {
+        val saveMode: SaveMode = null
+        Seq(1, 2).toDS().write.mode(saveMode).parquet(path.getAbsolutePath)
+      }
+      assert(e1.getErrorClass === "UNSUPPORTED_SAVE_MODE")
+      assert(e1.getMessage === "The save mode NULL is not supported for: a non-existent path.")
+
+      Utils.createDirectory(path)
+
+      val e2 = intercept[SparkIllegalArgumentException] {
+        val saveMode: SaveMode = null
+        Seq(1, 2).toDS().write.mode(saveMode).parquet(path.getAbsolutePath)
+      }
+      assert(e2.getErrorClass === "UNSUPPORTED_SAVE_MODE")
+      assert(e2.getMessage === "The save mode NULL is not supported for: an existent path.")
+    }
+  }
 }