On line 25 of the WA_Universal_Email/WAUE_test1_1.php file, I can see that you have only selected the serverDirectory for the attachment:
$WA_MailObject = WAUE_AddAttachment($WA_MailObject,"".$WA_DFP_UploadStatus["WA_UploadResult1"]["serverDirectory"] ."");
double click the Universal Email server behavior. On attachments tab, select the code that is already there for the server directory and copy it. Then click thye lightning bolt and select the server file name name.
Place your cursor at the beginning of the server file name code and paste the server directory code.
When you are done, line 25 should look like:
$WA_MailObject = WAUE_AddAttachment($WA_MailObject,"".$WA_DFP_UploadStatus["WA_UploadResult1"]["serverDirectory"] ."".$WA_DFP_UploadStatus["WA_UploadResult1"]["serverFileName"] ."");