Missing implementation for ToolsAPI interface method when upgrading to Delphi 10.4 Sydney

I have installed Delphi 10.4 Sydney w/ Patch 2 in a new virtual machine, and copied Delphi 10.3 Tokyo sources to it.

When rebuilding a visualizer (for DevExpress TcxSchedulerEvents) I get this error:

[dcc32 Error] EventVisualizr.pas(19): E2291 Missing implementation of interface method IOTAThreadNotifier.EvaluateComplete

I had only removed the compiled packages cxLibraryRS26, cxSchedulerRS26, dxCoreRS26, dxGDIPlusRS26, and added cxLibraryRS27, cxSchedulerRS27, dxCoreRS27, dxGDIPlusRS27 - no other code changes:

I get the error on the first line of the TEventViewerFrame type definition:

unit EventVisualizr;
// Copied and modified from TStringListVisualizer. Shows values for TcxSchedulerEvent properties:
// - ID
// - Caption
// - Custom property tt_fromdate (if it exists)
// - Custom property tt_todate (if it exists)
// - Start
// - Finish

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ComCtrls, ToolsAPI, Vcl.ExtCtrls;

type
  TAvailableState = (asAvailable, asProcRunning, asOutOfScope, asNotAvailable);

  TEventViewerFrame = class(TFrame, IOTADebuggerVisualizerExternalViewerUpdater, IOTAThreadNotifier, IOTAThreadNotifier160)
    EventListView: TListView;
    procedure EventListViewData(Sender: TObject; Item: TListItem);
  private
    FOwningForm: TCustomForm;
    FClosedProc: TOTAVisualizerClosedProcedure;
    FNotifierIndex: Integer;
    FCompleted: Boolean;
    FDeferredResult: string;
    FDeferredError: Boolean;
    FPropValues,
    FPropNames: TStrings;
    FAvailableState: TAvailableState;
    function Evaluate(Expression: string): string;
  protected
    procedure SetParent(AParent: TWinControl); override;
  public
    procedure CloseVisualizer;
    procedure MarkUnavailable(Reason: TOTAVisualizerUnavailableReason);
    procedure RefreshVisualizer(const Expression, TypeName, EvalResult: string);
    procedure SetClosedCallback(ClosedProc: TOTAVisualizerClosedProcedure);
    procedure SetForm(AForm: TCustomForm);
    procedure AddEventItems(const Expression, TypeName, EvalResult: string);

    { IOTAThreadNotifier }
    procedure AfterSave;
    procedure BeforeSave;
    procedure Destroyed;
    procedure Modified;
    procedure ThreadNotify(Reason: TOTANotifyReason);
    procedure EvaluteComplete(const ExprStr, ResultStr: string; CanModify: Boolean;
      ResultAddress, ResultSize: LongWord; ReturnCode: Integer);
    procedure ModifyComplete(const ExprStr, ResultStr: string; ReturnCode: Integer);

    { IOTAThreadNotifier160 }
    procedure EvaluateComplete(const ExprStr, ResultStr: string; CanModify: Boolean;
      ResultAddress: TOTAAddress; ResultSize: LongWord; ReturnCode: Integer);
  end;

In the ToolsAPI.pas, both have an EvaluateComplete definition, but no implementation in that source file:

IOTAThreadNotifier = interface(IOTANotifier)
  ['{34B2E2D7-E36F-11D1-AB0E-00C04FB16FB3}']
  { This is called when the process state changes for this thread }
  procedure ThreadNotify(Reason: TOTANotifyReason);
  { This is called when an evaluate that returned erDeferred completes.
    ReturnCode <> 0 if error }
  procedure EvaluateComplete(const ExprStr, ResultStr: string; CanModify: Boolean;
    ResultAddress, ResultSize: LongWord; ReturnCode: Integer);
  { This is called when a modify that returned erDeferred completes.
    ReturnCode <> 0 if error }
  procedure ModifyComplete(const ExprStr, ResultStr: string; ReturnCode: Integer);
end;

IOTAThreadNotifier160 = interface(IOTAThreadNotifier)
  ['{46F94C52-E225-4054-A5F0-F5E67E29B2C2}']
  { This is called when an evaluate that returned erDeferred completes.
    ReturnCode <> 0 if error }
  procedure EvaluateComplete(const ExprStr, ResultStr: string; CanModify: Boolean;
    ResultAddress: TOTAAddress; ResultSize: LongWord; ReturnCode: Integer); overload;
end;

When comparing ToolsAPI files, I see:

• It was named EvaluteComplete (missing 'a') in 10.3 and that has been fixed to EvaluateComplete
• The IOTAThreadNotifier160.EvaluateComplete now gets an overload directive (of course, and not relevant to the issue I think)

Could that name change be the reason? There are no 'implementation' for the EvaluateComplete procedures in the 10.3 version either (which seems to be fine, from the very little I know about interfaces).

From Why do I get the error Missing implementation of interface method in Delphi XE2? and Why do I get error Missing implementation?, I understand that the reason for the error can be that the parameter lists differ, but I have no idea where to look for the correct ones in this case.

Your TEventViewerFrame still contains the implementation for the 'old' EvaluteComplete.

Fix it by simply renaming TEventViewerFrame.EvaluteComplete to TEventViewerFrame.EvaluateComplete (to satisfy the new interface contract).