In some situations you may encounter the following error message in Easy365Manager:
This error message indicates that you haven’t configured the Azure AD Connect server name.
You must configure the name of your Azure AD Connect server to allow Easy365Manager to trigger synchronization between your local AD and Office 365.
If you have installed Easy365Manager on your Azure AD Connect server you can set the server to “127.0.0.1” or “localhost”.
To read more about Azure AD Connect refer to this article.
For general information on the prerequisites of Easy365Manager, have a look at the official documentation.