Plesk update, upgrade or installation failed with the following error message:
MSI: Error! Error writing to file: C:\\Config.Msi\\e56001.rbf. Verify that you have access to that directory.
Failed to install 'C:\\ParallelsInstaller\\parallels\\PANEL-WIN_12.5.30\\dist-msi-Microsoft-2003-i386\\plesk-skins.msi': Fatal error during installation. (Error code 1603)
OS misconfiguration or third-party utilities block access to C:\Config.Msi\ folder.
Turn off any Firewall installed. You may turn it on back when update is completed;
Turn off any Anti-Virus software on a server;
Turn off any backup managers and make sure that there are no running tasks related to a backup manager;
Run update again.
If it does not help:
AdministratorsFullControl permission granted.
Decrease notify level in Windows "User Account Control Settings" to "Don't notify me when I make changes to Windows Settings".
Add 'Everyone' with 'FullControl' permissions to