If an attachment contains a "#" symbol in the name, then the attachment appears to attach correctly, but fails when trying to view it. Changing the file name to remove the "#" is a successful workaround.
However, the bigger issue here is that there is no error message provided to the user when an attachment fails and it requires follow-up to obtain the original attachment. That condition exists also when a user attempts to attach a file whose file type is not included in HDP configuration-- no message is provided to the user, but the attachment is unsuccessful.
