diff --git a/sane/scanner.cpp b/sane/scanner.cpp
index 68ed065..3bf5b63 100644
--- a/sane/scanner.cpp
+++ b/sane/scanner.cpp
@@ -293,6 +293,11 @@ int scanner::open(void)
 		load_config((cfg_path_ + scanner_name_).c_str());
 		// apply_config();
 	}
+	else
+	{
+		std::wstring	msg(local_trans::a2u(hg_scanner_err_description(ret), CP_UTF8));
+		MessageBoxW(NULL, msg.c_str(), L"\u6253\u5F00\u5931\u8D25", MB_OK | MB_ICONERROR);
+	}
 
 	return ret;
 }
@@ -1689,9 +1694,16 @@ COM_API_IMPLEMENT(scanner, int, start(void))
 			img_fmt_.img_format = SANE_IMAGE_TYPE_BMP;
 		img_fmt_.compress.compression = cmprsn;
 	}
-	else if (indicator_.get())
+	//else if (indicator_.get())
+	//{
+	//	indicator_->notify_scan_over(hg_scanner_err_description(ret), true);
+	//}
+	else
 	{
-		indicator_->notify_scan_over(hg_scanner_err_description(ret), true);
+		std::wstring	msg(local_trans::a2u(hg_scanner_err_description(ret), CP_UTF8));
+		if (indicator_.get())
+			indicator_.reset();
+		MessageBoxW(NULL, msg.c_str(), L"\u542F\u52A8\u5931\u8D25", MB_OK | MB_ICONERROR);
 	}
 	prev_start_result_ = ret;
 	is_scanning_ = ret == SANE_STATUS_GOOD;
@@ -2237,7 +2249,10 @@ int scanner::handle_device_event(int ev_code, void* data, unsigned int* len)
 
 	return 0;
 }
-
+int scanner::last_error(void)
+{
+	return err_;
+}
 
 
 
@@ -2337,9 +2352,21 @@ int __stdcall open_scanner(SCANNERID scanner_id, ISaneInvoker** invoker)
 		return SCANNER_ERR_DEVICE_NOT_FOUND;
 
 	scanner* scn = new scanner(scanner_id);
-	*invoker = dynamic_cast<ISaneInvoker*>(scn);
+	if (scn->last_error() == SCANNER_ERR_OK)
+	{
+		*invoker = dynamic_cast<ISaneInvoker*>(scn);
 
-	return 0;
+		return 0;
+	}
+	else
+	{
+		int ret = scn->last_error();
+
+		scn->release();
+		*invoker = NULL;
+
+		return ret;
+	}
 }
 #ifdef EXPORT_SANE_API
 __declspec(dllexport)
diff --git a/sane/scanner.h b/sane/scanner.h
index 5731221..e79e1fb 100644
--- a/sane/scanner.h
+++ b/sane/scanner.h
@@ -325,4 +325,5 @@ public:
 	// methods:
 public:
 	int handle_device_event(int ev_code, void* data, unsigned int* len);
+	int last_error(void);
 };
\ No newline at end of file
diff --git a/twain/twain/huagaods.cpp b/twain/twain/huagaods.cpp
index c662ccd..cb3d1dd 100644
--- a/twain/twain/huagaods.cpp
+++ b/twain/twain/huagaods.cpp
@@ -679,6 +679,8 @@ Twpp::ConditionCode huagao_ds::condition_code_from_hg_error(int hgerr)
 		return Twpp::ConditionCode::DamagedCorner;
 	if (hgerr == SCANNER_ERR_DEVICE_NO_PAPER)
 		return Twpp::ConditionCode::NoMedia;
+	if (hgerr == SCANNER_ERR_OPENED_BY_OTHER_PROCESS)
+		return Twpp::ConditionCode::MaxConnections;
 
 	return (Twpp::ConditionCode)((int)Twpp::ConditionCode::CustomBase + hgerr);
 }
@@ -921,13 +923,16 @@ Result huagao_ds::userInterfaceEnable(const Identity&, UserInterface& ui)
 			return seqError();
 
 		scanner_->twain_set_transfer((twain_xfer)m_capXferMech);
-
-		if (scanner_->start() == SCANNER_ERR_OK)
+		int err = scanner_->start();
+		if (err == SCANNER_ERR_OK)
 		{
 			return success();
 		}
 		else
 		{
+			if (err == SCANNER_ERR_DEVICE_NO_PAPER)
+				return { ReturnCode::Failure,  ConditionCode::NoMedia };
+
 			return bummer();
 		}
 	}