diff --git a/DesktopEditor/doctrenderer/drawingfile.h b/DesktopEditor/doctrenderer/drawingfile.h
index b6433c67cd..c70773878e 100644
--- a/DesktopEditor/doctrenderer/drawingfile.h
+++ b/DesktopEditor/doctrenderer/drawingfile.h
@@ -295,6 +295,12 @@ public:
 			return ((CPdfFile*)m_pFile)->MergePages(data, size, nMaxID, sPrefixForm);
 		return false;
 	}
+	bool UnmergePages()
+	{
+		if (m_nType == 0)
+			return ((CPdfFile*)m_pFile)->UnmergePages();
+		return false;
+	}
 
 	BYTE* GetGlyphs(int nPageIndex)
 	{
diff --git a/DesktopEditor/graphics/pro/js/drawingfile.json b/DesktopEditor/graphics/pro/js/drawingfile.json
index efd27ff4eb..aa16b7cd1f 100644
--- a/DesktopEditor/graphics/pro/js/drawingfile.json
+++ b/DesktopEditor/graphics/pro/js/drawingfile.json
@@ -53,6 +53,7 @@
 		"_ScanPage",
 		"_SplitPages",
 		"_MergePages",
+		"_UnmergePages",
 		"_GetImageBase64",
 		"_GetImageBase64Len",
 		"_GetImageBase64Ptr",
diff --git a/DesktopEditor/graphics/pro/js/wasm/js/drawingfile.js b/DesktopEditor/graphics/pro/js/wasm/js/drawingfile.js
index f18e773cf4..642dc0d451 100644
--- a/DesktopEditor/graphics/pro/js/wasm/js/drawingfile.js
+++ b/DesktopEditor/graphics/pro/js/wasm/js/drawingfile.js
@@ -176,6 +176,10 @@ CFile.prototype["MergePages"] = function(arrayBuffer, maxID, prefixForm)
 {
 	return this._MergePages(arrayBuffer, maxID, prefixForm);
 };
+CFile.prototype["UndoMergePages"] = function()
+{
+	return this._UndoMergePages();
+};
 
 // INFO DOCUMENT
 CFile.prototype.getInfo = function()
diff --git a/DesktopEditor/graphics/pro/js/wasm/js/drawingfile_wasm.js b/DesktopEditor/graphics/pro/js/wasm/js/drawingfile_wasm.js
index f3d5fd70bb..1c793c5492 100644
--- a/DesktopEditor/graphics/pro/js/wasm/js/drawingfile_wasm.js
+++ b/DesktopEditor/graphics/pro/js/wasm/js/drawingfile_wasm.js
@@ -162,6 +162,17 @@ CFile.prototype._MergePages = function(buffer, maxID, prefixForm)
 	return bRes == 1;
 };
 
+CFile.prototype._UndoMergePages = function()
+{
+	let bRes = Module["_UnmergePages"](this.nativeFile);
+	if (bRes == 1)
+	{
+		let str = this.stream.pop();
+		Module["_free"](str);
+	}
+	return bRes == 1;
+};
+
 // FONTS
 CFile.prototype._isNeedCMap = function()
 {
diff --git a/DesktopEditor/graphics/pro/js/wasm/src/drawingfile.cpp b/DesktopEditor/graphics/pro/js/wasm/src/drawingfile.cpp
index 7d8b199539..3337e609a8 100644
--- a/DesktopEditor/graphics/pro/js/wasm/src/drawingfile.cpp
+++ b/DesktopEditor/graphics/pro/js/wasm/src/drawingfile.cpp
@@ -185,6 +185,10 @@ WASM_EXPORT int MergePages(CDrawingFile* pFile, BYTE* data, LONG size, int nMaxI
 {
 	return pFile->MergePages(data, size, nMaxID, sPrefixForm) ? 1 : 0;
 }
+WASM_EXPORT int UnmergePages(CDrawingFile* pFile)
+{
+	return pFile->UnmergePages() ? 1 : 0;
+}
 
 WASM_EXPORT void* GetImageBase64(CDrawingFile* pFile, int rId)
 {
diff --git a/DesktopEditor/graphics/pro/js/wasm/src/drawingfile_test.cpp b/DesktopEditor/graphics/pro/js/wasm/src/drawingfile_test.cpp
index 0728a890c9..6ec6f8b4de 100644
--- a/DesktopEditor/graphics/pro/js/wasm/src/drawingfile_test.cpp
+++ b/DesktopEditor/graphics/pro/js/wasm/src/drawingfile_test.cpp
@@ -993,7 +993,7 @@ int main(int argc, char* argv[])
 
 	// SPLIT & MERGE
 	BYTE* pSplitPages = NULL;
-	if (false)
+	if (true)
 	{
 		std::vector<int> arrPages = { 0 };
 		for (int i = 0; i < 3; i++)
@@ -1010,11 +1010,14 @@ int main(int argc, char* argv[])
 
 				if (MergePages(pGrFile, pSplitPages + 4, nLength - 4, 0, "merge") == 0)
 					RELEASEARRAYOBJECTS(pSplitPages);
+
+				if (!UnmergePages(pGrFile))
+					std::cout << "error" << std::endl;
 			}
 		}
 	}
 	BYTE* pFileMerge = NULL;
-	if (true)
+	if (false)
 	{
 		DWORD nFileMergeLen = 0;
 		if (NSFile::CFileBinary::ReadAllBytes(NSFile::GetProcessDirectory() + L"/test_merge.pdf", &pFileMerge, nFileMergeLen))
diff --git a/PdfFile/PdfEditor.cpp b/PdfFile/PdfEditor.cpp
index a214c48cf0..6359e7c922 100644
--- a/PdfFile/PdfEditor.cpp
+++ b/PdfFile/PdfEditor.cpp
@@ -618,10 +618,22 @@ HRESULT _ChangePassword(const std::wstring& wsPath, const std::wstring& wsPasswo
 		}
 		case objString:
 		{
-			TextString* s = new TextString(oTemp.getString());
-			std::string sValue = NSStringExt::CConverter::GetUtf8FromUTF32(s->getUnicode(), s->getLength());
-			pObj = new PdfWriter::CStringObject(sValue.c_str());
-			delete s;
+			GString* str = oTemp.getString();
+			if (str->isBinary())
+			{
+				int nLength = str->getLength();
+				BYTE* arrId = new BYTE[nLength];
+				for (int nIndex = 0; nIndex < nLength; ++nIndex)
+					arrId[nIndex] = str->getChar(nIndex);
+				pObj = new PdfWriter::CBinaryObject(arrId, nLength, false);
+			}
+			else
+			{
+				TextString* s = new TextString(str);
+				std::string sValue = NSStringExt::CConverter::GetUtf8FromUTF32(s->getUnicode(), s->getLength());
+				pObj = new PdfWriter::CStringObject(sValue.c_str(), !s->isPDFDocEncoding());
+				delete s;
+			}
 			break;
 		}
 		case objName:
diff --git a/PdfFile/PdfFile.cpp b/PdfFile/PdfFile.cpp
index b63f38e503..25012f6c1a 100644
--- a/PdfFile/PdfFile.cpp
+++ b/PdfFile/PdfFile.cpp
@@ -341,6 +341,12 @@ bool CPdfFile::MergePages(BYTE* data, DWORD length, int nMaxID, const std::strin
 		return false;
 	return m_pInternal->pReader->MergePages(data, length, L"", nMaxID, sPrefixForm) && (m_pInternal->pReader->GetError() == 0);
 }
+bool CPdfFile::UnmergePages()
+{
+	if (!m_pInternal->pReader)
+		return false;
+	return m_pInternal->pReader->UnmergePages();
+}
 int CPdfFile::GetRotate(int nPageIndex)
 {
 	if (!m_pInternal->pReader)
diff --git a/PdfFile/PdfFile.h b/PdfFile/PdfFile.h
index 8187bfdbea..5ac8c1624e 100644
--- a/PdfFile/PdfFile.h
+++ b/PdfFile/PdfFile.h
@@ -128,6 +128,7 @@ public:
 
 	bool ValidMetaData();
 	bool MergePages(BYTE* data, DWORD length, int nMaxID = 0, const std::string& sPrefixForm = "");
+	bool UnmergePages();
 	int GetRotate(int nPageIndex);
 	int GetMaxRefID();
 	BYTE* GetWidgets();
diff --git a/PdfFile/PdfReader.cpp b/PdfFile/PdfReader.cpp
index 3ba5a28968..42e178872e 100644
--- a/PdfFile/PdfReader.cpp
+++ b/PdfFile/PdfReader.cpp
@@ -643,6 +643,15 @@ bool CPdfReader::MergePages(const std::wstring& wsFile, const std::wstring& wsPa
 
 	return true;
 }
+bool CPdfReader::UnmergePages()
+{
+	if (m_vPDFContext.size() < 1)
+		return false;
+	CPdfReaderContext* pPDFContext = m_vPDFContext.back();
+	delete pPDFContext;
+	m_vPDFContext.pop_back();
+	return true;
+}
 void CPdfReader::DrawPageOnRenderer(IRenderer* pRenderer, int _nPageIndex, bool* pbBreak)
 {
 	PDFDoc* pDoc = NULL;
diff --git a/PdfFile/PdfReader.h b/PdfFile/PdfReader.h
index e02874cc50..a95d43f3d3 100644
--- a/PdfFile/PdfReader.h
+++ b/PdfFile/PdfReader.h
@@ -79,6 +79,7 @@ public:
 	bool ValidMetaData();
 	bool MergePages(BYTE* pData, DWORD nLength, const std::wstring& wsPassword = L"", int nMaxID = 0, const std::string& sPrefixForm = "");
 	bool MergePages(const std::wstring& wsFile, const std::wstring& wsPassword = L"", int nMaxID = 0, const std::string& sPrefixForm = "");
+	bool UnmergePages();
 	void GetPageInfo(int nPageIndex, double* pdWidth, double* pdHeight, double* pdDpiX, double* pdDpiY);
 	void DrawPageOnRenderer(IRenderer* pRenderer, int nPageIndex, bool* pBreak);
 	std::wstring GetInfo();