SymptomsControl Panel appears grayed out, so any user input is unavailable.
Browsers: Safari, Google Chrome, Konqueror.
ResolutionThe solution is available for the 18.104.22.16891 version. You should update Helm to 4.2.0 before applying the patch. For instructions on how to perform the update, see http://helm.download.webhostautomation.net/release-notes/4.2.0/Parallels-Helm-4.2.0-Release-Notes.html#3 .
Replace C:\Program Files\Parallels\Helm4\ControlPanel\ClientScripts\fog_screen.js with the attached file in the affected Control server.