Error during token refresh

I have configured a SCIM connector with client certificate authentication method and after a lot of trial and error I managed to establish the connection between One Identity and the Target System.

The problem starts when I try to browse the users and groups. At first I get the below error message.

[1777009] Error loading system objects of class User (all) (User_Master).
     at VI.Projector.UI.Controls.ObjectBrowserControl._TreeListTypesNodeActivateHandler(Object sender, TreeListEventArgs e)
     at VI.Projector.UI.Controls.ObjectBrowserControl._LoadResult(ISchemaClass schemaClass)
     at VI.Projector.Connection.SystemConnection.QueryObjectInternal(ISchemaClass schemaClass, QueryByFilterOptions query, Boolean withScope)
Exception has been thrown by the target of an invocation.
     at VI.Projector.Connection.SystemConnection.QueryObjectInternal(ISchemaClass schemaClass, QueryByFilterOptions query, Boolean withScope)
     at VI.Projector.Connection.Connectors.DistributionConnector.QueryObject(QueryObjectsRequest request)
     at VI.Projector.Connection.Connectors.ThreadSafeConnector.OnQueryObject(QueryObjectsRequest request)
     at VI.Projector.Connection.SystemConnector.QueryObject(QueryObjectsRequest request)
     at VI.Projector.SCIM.Connector.ProjectorSCIMConnector.OnQueryObjectsByFilter(QueryObjectsByFilterRequest request)
     at VI.Projector.ProjectorBaseConnector.InvokeMethod(String MethodName, Object[] Arguments)
     at System.RuntimeType.InvokeMember(String name, BindingFlags bindingFlags, Binder binder, Object target, Object[] providedArgs, ParameterModifier[] modifiers, CultureInfo culture, String[] namedParams)
     at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
     at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments)
     at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
The second error mesage I get, is shown below

[1777009] Error loading system objects of class User (all) (User_Master).

     at VI.Projector.UI.Controls.ObjectBrowserControl._TreeListTypesNodeActivateHandler(Object sender, TreeListEventArgs e)

     at VI.Projector.UI.Controls.ObjectBrowserControl._LoadResult(ISchemaClass schemaClass)

     at VI.Projector.Connection.SystemConnection.QueryObjectInternal(ISchemaClass schemaClass, QueryByFilterOptions query, Boolean withScope)

[1777384] : Error while reading User objects with properties ().

     at VI.Projector.Connection.SystemConnection.QueryObjectInternal(ISchemaClass schemaClass, QueryByFilterOptions query, Boolean withScope)

     at VI.Projector.Connection.Connectors.DistributionConnector.QueryObject(QueryObjectsRequest request)

     at VI.Projector.Connection.Connectors.ThreadSafeConnector.OnQueryObject(QueryObjectsRequest request)

     at VI.Projector.Connection.SystemConnector.QueryObject(QueryObjectsRequest request)

     at VI.Projector.SCIM.Connector.ProjectorSCIMConnector.OnQueryObjectsByFilter(QueryObjectsByFilterRequest request)

     at VI.Projector.ProjectorBaseConnector.HandleException(ObjectRequest Request, Exception Ex, Object[] MethodArguments, String MethodName)

Error during token refresh.

     at VI.Projector.NativeSystemSupport.NativeSystemConnection.ReadStreamed(NSCReadRequest request)

     at VI.Projector.SCIM.Connector.SCIMNativeSystemConnection.OnReadStreamed(NSCReadRequest request)

     at VI.Projector.SCIM.Connector.SCIMOperation.GetDirectoryObjectList(ProjectorSCIMConnectorSchemaType SchemaType, String NativeFilter, Boolean FindOne)

     at VI.Projector.SCIM.Connector.RESTConnection.GetObjectListDict(String endpoint, String filter, Boolean findOne)

     at VI.Projector.SCIM.Connector.RESTConnection.Call(String endPoint, String method, IDictionary`2 data, String query, List`1 AcceptedStatusCodes)

     at VI.Projector.SCIM.Connector.Request.Send(IList`1 acceptedStatusCodes)

Does anybody have any idea what is going wrong?