The error message ECOM00210 translates to “Upload Error: Authentication failure”
This error is directly related to your login details. Please double check that your username and password are correct. Also. when you enter in details for the username for your destination URL, you must ensure that you specify non-encoded characters by their proper hexadecimal equivalent. For example, if '@' is part of your username, you must replace the '@' in the username part of your destination URL with '%40'.