MailEnable is a very easy to use and efficient Email Server with lots of facilities and functionalists. Even a non-technical system administrator can also install and configure it without any assistance. You only need to run the setup and it will configure everything else for you.
The above error can occur if you are upgrading from a very old version to a latest available which will replace all the GUI things along with lots of new features offered.
The solution for this error is to stop all the MailEnable web services using IIS.
- Install the Upgrade using the MailEnable Setup
- Open the MailEnable Admin and go to webmail
- Right click on webmail and go to properties
- Go to site options and press the configure button
- select the site and press the install webmail
- Restart the IIS and you are done.