RuntimeException: scala.Some is not a valid external type for schema of string

I’m trying to read an Excel file in Java using the spark-excel library. It appears that the returned data is wrapped in scala.Some type.

Here is how I invoke the library:

        Dataset<Row> extractedExcel = sparkSession
                .read()
                .format("com.crealytics.spark.excel")
                .option("inferSchema", "false")
                .option("treatEmptyValuesAsNulls", "false")
                .option("useHeader", "true")
                // .schema(schema)
                .load(absPath);

Then, if I make any call on the resulting dataset, say extractedExcel.show(); or try to write the dataset out, I run into an exception:

Caused by: java.lang.RuntimeException: scala.Some is not a valid external type for schema of string
	at org.apache.spark.sql.catalyst.expressions.GeneratedClass$SpecificUnsafeProjection.StaticInvoke_0$(Unknown Source)
	at org.apache.spark.sql.catalyst.expressions.GeneratedClass$SpecificUnsafeProjection.apply(Unknown Source)
	at org.apache.spark.sql.catalyst.encoders.ExpressionEncoder.toRow(ExpressionEncoder.scala:324)

The error message suggests that the returned dataset wraps values in a scala.Some. I don’t see how can the values be unwrapped and turned into plain strings.