Failed to load dataset because of the following error:
Unable to Find connection ‘xyzConnectionString (Settings)1' For object ‘Settings’. The connection string could not be found in application settings, or the data provider associated with the connection string could not be loaded.

Solution:
It's so simple ...
Go to your xyzDataSet.xsd code and remove the one of duplicate Connection tags like below
<Connection AppSettingsObjectName="Settings" AppSettingsPropertyName="xyzConnectionString" ConnectionStringObject="" IsAppSettingsProperty="True" Modifier="Assembly" Name="xyzConnectionString (Settings)" ParameterPrefix="@" PropertyReference="ApplicationSettings.xyzDataLayer.Properties.Settings.GlobalReference.Default.xyzConnectionString" Provider="System.Data.SqlClient"></Connection>