If on a Plesk Windows platform, running Odin Version 12, you run across the below error, it is due to a few known bugs in previous Odin Updates which require a reinstallation of Micro Updates
An Example is the below, when trying to Login to the Panel, Update an Email address, or perform a normal Change.
The Most Simplest Fix, is to open CMD Prompt, and use the following command to issue a "reinstall" or "install" of all micro-updates for the currently running version.
ai.exe --select-product-id panel --select-release-current --reinstall-patch --install-component base
The Above path would normally be
C:\Program Files (x86)\Parallels\Plesk\admin\bin
This is Related to http://kb.odin.com/124398