@MurariSreenivasulu can you make sure the file is being read in binary mode. Sometimes, if the file is read as text instead of binary, it leads to incorrect Base64 encoding and garbage values when decoding. Also, verify that the MIME type is correctly set to application/vnd.openxmlformats-officedocument.wordprocessingml.document. Check if the clipboard or property used to hold the Base64 string is of type Text (Unlimited) to prevent data truncation. Finally, ensure that no extra characters or line breaks are being added during the conversion or transfer, as they can corrupt the Base64 string. Please let me know how it goes. thanks