SYMPTOMS
Plesk backup hangs backing up mail content.
The following warning is displayed:
Saving...
Wait for mail content...
Mail content saving
Warning:Acounts are not given. Please enter valid accounts information manually
RESOLUTION
Please download the following file
http://download1.swsoft.com/Plesk/Autoupdate/Windows/8.3.0/129806/psabackup.dll
and place it to the %plesk_bin% folder
Note: Please see how to install Plesk hotfixes properly.
Additional information
%plesk_dir% is environment variable which points to Plesk installation folder. By default it is C:\Program Files\SWsoft\Plesk
%plesk_bin% is environment variable which points to Plesk binaries folder. By default it is C:\Program Files\SWsoft\Plesk\admin\bin