Many of our SPO Sites are not shown in connection. How do we migrate content to sites new modern sites that were created in SPOnline?

I am getting the following error when I try to copy an existing subsite from 2010 to an existing modern site. I’m using a Remote Connection (SharePoint Client Side Object Model 2013). Can we schedule a call? I don’t understand your statement that content matrix has not been fully tested with Modern Sites. They have been available for a long time. Error: Message: An error occurred during the operation of a service method: The web template GROUP#0 is not available for sites on this tenant. Stack Trace: at Microsoft.SharePoint.Client.ClientRequest.ProcessResponseStream(Stream responseStream) at Microsoft.SharePoint.Client.ClientRequest.ProcessResponse() at Metalogix.SharePoint.Adapters.CSOM2013.CSOMAdapter.CreateSiteCollectionWithIncrementalRetry(ClientContext ctx, Tenant tenant, SiteCreationProperties siteCreationData, Int32 retryCount, Int32 delay) at Metalogix.SharePoint.Adapters.CSOM2013.CSOMAdapter.AddSiteCollection(String webApp, String siteCollectionXML, AddSiteCollectionOptions addSiteCollOptions) at SyncInvokeAddSiteCollection(Object , Object[] , Object[] ) at System.ServiceModel.Dispatcher.SyncMethodInvoker.Invoke(Object instance, Object[] inputs, Object[]& outputs) at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeBegin(MessageRpc& rpc) at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage5(MessageRpc& rpc) at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage11(MessageRpc& rpc) at System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet) Stack: at Metalogix.SharePoint.Actions.Administration.CreateSiteCollection.RunAction(IXMLAbleList source, IXMLAbleList target) at Metalogix.Actions.Action.Run(IXMLAbleList source, IXMLAbleList target) Type: System.Exception HResult:-2146233088

I am getting the following error when I try to copy an existing subsite from 2010 to an existing modern site. I’m using a Remote Connection (SharePoint Client Side Object Model 2013). Can we schedule a call? I don’t understand your statement that content matrix has not been fully tested with Modern Sites. They have been available for a long time. Error: Message: An error occurred during the operation of a service method: The web template GROUP#0 is not available for sites on this tenant. Stack Trace: at Microsoft.SharePoint.Client.ClientRequest.ProcessResponseStream(Stream responseStream) at Microsoft.SharePoint.Client.ClientRequest.ProcessResponse() at Metalogix.SharePoint.Adapters.CSOM2013.CSOMAdapter.CreateSiteCollectionWithIncrementalRetry(ClientContext ctx, Tenant tenant, SiteCreationProperties siteCreationData, Int32 retryCount, Int32 delay) at Metalogix.SharePoint.Adapters.CSOM2013.CSOMAdapter.AddSiteCollection(String webApp, String siteCollectionXML, AddSiteCollectionOptions addSiteCollOptions) at SyncInvokeAddSiteCollection(Object , Object[] , Object[] ) at System.ServiceModel.Dispatcher.SyncMethodInvoker.Invoke(Object instance, Object[] inputs, Object[]& outputs) at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeBegin(MessageRpc& rpc) at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage5(MessageRpc& rpc) at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage11(MessageRpc& rpc) at System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet) Stack: at Metalogix.SharePoint.Actions.Administration.CreateSiteCollection.RunAction(IXMLAbleList source, IXMLAbleList target) at Metalogix.Actions.Action.Run(IXMLAbleList source, IXMLAbleList target) Type: System.Exception HResult:-2146233088