Salesforce Data Loader supports in both the versions Salesforce Classic and Lightning Experience and it is available in different editions, for example, Enterprise Edition, Unlimited Edition, Performance Edition, Developer Edition and Database.com Edition. In Salesforce after exporting and importing the data, the Data Loader generates two CSV output files which contain the results of the operation. The First file of the two generated CSV files starts with the “success”, and the second one starts with “error.”

So, we can use the Data Loader CSV file viewer to open the files:

1. In the Data Loader page, Choose View and after View CSV.
2. Now, to specify the number of rows to the view. Each one of the row in the CSV file corresponds to one Salesforce record. The default is 1,000.
3. Now, to view a specific CSV file, click Open CSV, and for viewing the last success file, click Open Success. To view the last error file, click Open Error.
4. Next, to open the file in an external program, such as Excel, click Open in External Program.
5. Next, the “success” file contains all the successfully loaded records. The file includes a column with the newly generated record IDs, and the “error” file contains all the rejected records. The file has a column that describes why the load failed.
6. At Last, to return to the CSV Chooser window, click Close. To exit the window, click OK.