Hi Aditya,
This issue was due to missing config in Back end. Please maintain the proper config in DC10, DC20 and DC30 transactions.
I would rather suggest to check the Back end config for your document type and work station application . Try to upload a document in to ECC using CV01N transaction using the document type you are using. If the document got uploaded successfully then we can confirm that we are good with our back end config , then try the FM again.
Please let me know if any queries.
Thanks&Regards,
Aishwarya.M