Hi Ray, I'm most certain that all dependent files have been uploaded - I don't use DW to upload my files to the remote server but do it all with a separate FTP client (as have seen what DW can & can't do in the past!).
To confirm that you could take a look at http://charlienailsandbeauty.co.uk/webassist/email/templates/Blank_2.php to see the bones of the test template file that's been uploaded and which is being referenced in the script.
To me it seems that the error is coming somewhere in the mailformatting_php.php which doesn't seem to see / prepend the path to the script (ie in the templates sub-directory) leaving it to look in the root directory for it!
Just to confirm; I'm using DW CS4 on a PC running Windows 8.1 and the WA extension UE4.0.1 and trying to use PEAR Mail