The following error shown in the Control Panel
The file '/Skins/B9106EEE-DB03-489D-A19D-8647A55EC15C/control/login_2.ascx' does not exist.
Could not load file or assembly 'Parallels.Helm.ControlPanel.Skins.XPreloaded' or one of its dependencies. The system cannot find the file specified.
Some files are missing.
Try to reinstall all modules according to the following KB article:
If the solution did not help, check that all skins are installed.