创建TRESTClient时出错：“没有注册带有guid [{}]的接口的对等体

TFrwWebServiceREST = class(TInterfacedObject,IRESTWebServiceProxy)
private
  FClientRest: TRESTClient;
  FRequestRest: TRESTRequest;
  FResponseRest: TRESTResponse;
public
  constructor Create (AUrl: string); virtual;
end;

...

constructor TFrwWebServiceREST.Create(AUrl: string);
begin
  FClientRest := TRESTClient.Create (AUrl); //the error occurs here
  FClientRest.AcceptEncoding := 'UTF-8';
  FResponseRest := TRESTResponse.Create (nil);
  FResponseRest.ContentEncoding := 'UTF-8';
  FRequestRest := TRESTRequest.Create (nil);
  FRequestRest.AcceptEncoding := 'UTF-8';
  FRequestRest.Response := FResponseRest;
  FRequestRest.Client := FClientRest;
end;

错误并不总是发生…该过程完美地运行,然后一段时间后,此错误开始发生.

First chance exception at $7656C54F. Exception class EIPAbstractError with message ‘No peer with the interface with guid {B8BD5BD8-C39D-4DF1-BB14-625FC86029DB} has been registered’.

创建RESTClient时会引发异常.它能是什么？