SYMPTOMS
Trying to browse Plesk, Domains, domain.tld, Web Applications page returns the following warning:
Notice: Undefined variable: sa_rel in
E:\Progs\SWsoft\Plesk\admin\plib\SiteApps\class.SiteAppPackageManager.php on
line 476
RESOLUTION
Please download the following file
http://download1.swsoft.com/Plesk/Autoupdate/Windows/8.3.0/128717/class.SiteAppPackageManager.php
and place it to the %plesk_dir%admin\plib\SiteApps 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