diff --git a/PowerEditor/src/Notepad_plus.cpp b/PowerEditor/src/Notepad_plus.cpp
index bd5a85636..60c22219d 100644
--- a/PowerEditor/src/Notepad_plus.cpp
+++ b/PowerEditor/src/Notepad_plus.cpp
@@ -1331,6 +1331,7 @@ bool Notepad_plus::replaceInOpenedFiles()
 	}
 
 	_invisibleEditView.execute(SCI_SETDOCPOINTER, 0, oldDoc);
+
 	_invisibleEditView.setCurrentBuffer(oldBuf);
 	_pEditView = pOldView;
 
@@ -3875,7 +3876,9 @@ void Notepad_plus::setLanguage(LangType langType)
 			reset = true;
 			_subEditView.saveCurrentPos();
 			prev = _subEditView.execute(SCI_GETDOCPOINTER);
+			_subEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_OFF);
 			_subEditView.execute(SCI_SETDOCPOINTER, 0, 0);
+			_subEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_ON);
 		}
 	}
 	
@@ -3890,7 +3893,9 @@ void Notepad_plus::setLanguage(LangType langType)
 
 	if (reset)
 	{
+		_subEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_OFF);
 		_subEditView.execute(SCI_SETDOCPOINTER, 0, prev);
+		_subEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_ON);
 		_subEditView.restoreCurrentPosPreStep();
 	}
 }
@@ -4662,6 +4667,10 @@ void Notepad_plus::loadBufferIntoView(BufferID id, int whichOne, bool dontClose)
 		{
 			idToClose = BUFFER_INVALID;
 		}
+		else
+		{
+			buf->setLastLangType(-1); // When replacing the "new" tab with an opened file, the last used language should be reset to its initial value so that the language can be reloaded later in the activateBuffer() function.
+		}
 	}
 
 	MainFileManager.addBufferReference(id, viewToOpen);
diff --git a/PowerEditor/src/NppCommands.cpp b/PowerEditor/src/NppCommands.cpp
index b641c6a0d..c3dea4dec 100644
--- a/PowerEditor/src/NppCommands.cpp
+++ b/PowerEditor/src/NppCommands.cpp
@@ -3713,10 +3713,13 @@ void Notepad_plus::command(int id)
 		case IDM_LANG_TOML:
 		case IDM_LANG_USER :
 		{
-            setLanguage(menuID2LangType(id));
+			LangType lang = menuID2LangType(id);
+			setLanguage(lang);
+
 			// Manually set language, don't change language even file extension changes.
 			Buffer *buffer = _pEditView->getCurrentBuffer();
 			buffer->langHasBeenSetFromMenu();
+			buffer->setLastLangType(static_cast<int>(lang));
 
 			if (_pDocMap)
 			{
diff --git a/PowerEditor/src/NppIO.cpp b/PowerEditor/src/NppIO.cpp
index 13c4f4e3a..18c03efa6 100644
--- a/PowerEditor/src/NppIO.cpp
+++ b/PowerEditor/src/NppIO.cpp
@@ -574,13 +574,17 @@ bool Notepad_plus::doReload(BufferID id, bool alert)
 	if (mainVisisble)
 	{
 		_mainEditView.saveCurrentPos();
+		_mainEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_OFF);
 		_mainEditView.execute(SCI_SETDOCPOINTER, 0, 0);
+		_mainEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_ON);
 	}
 
 	if (subVisisble)
 	{
 		_subEditView.saveCurrentPos();
+		_subEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_OFF);
 		_subEditView.execute(SCI_SETDOCPOINTER, 0, 0);
+		_subEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_ON);
 	}
 
 	if (!mainVisisble && !subVisisble)
@@ -592,13 +596,17 @@ bool Notepad_plus::doReload(BufferID id, bool alert)
 	Buffer * pBuf = MainFileManager.getBufferByID(id);
 	if (mainVisisble)
 	{
+		_mainEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_OFF);
 		_mainEditView.execute(SCI_SETDOCPOINTER, 0, pBuf->getDocument());
+		_mainEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_ON);
 		_mainEditView.restoreCurrentPosPreStep();
 	}
 
 	if (subVisisble)
 	{
+		_subEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_OFF);
 		_subEditView.execute(SCI_SETDOCPOINTER, 0, pBuf->getDocument());
+		_subEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_ON);
 		_subEditView.restoreCurrentPosPreStep();
 	}
 
@@ -2473,12 +2481,16 @@ bool Notepad_plus::loadSession(Session & session, bool isSnapshotMode, const wch
 			//Force in the document so we can add the markers
 			//Don't use default methods because of performance
 			Document prevDoc = _mainEditView.execute(SCI_GETDOCPOINTER);
+			_mainEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_OFF);
 			_mainEditView.execute(SCI_SETDOCPOINTER, 0, buf->getDocument());
+			_mainEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_ON);
 			for (size_t j = 0, len = session._mainViewFiles[i]._marks.size(); j < len ; ++j)
 			{
 				_mainEditView.execute(SCI_MARKERADD, session._mainViewFiles[i]._marks[j], MARK_BOOKMARK);
 			}
+			_mainEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_OFF);
 			_mainEditView.execute(SCI_SETDOCPOINTER, 0, prevDoc);
+			_mainEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_ON);
 			++i;
 		}
 		else
@@ -2604,12 +2616,16 @@ bool Notepad_plus::loadSession(Session & session, bool isSnapshotMode, const wch
 			//Force in the document so we can add the markers
 			//Don't use default methods because of performance
 			Document prevDoc = _subEditView.execute(SCI_GETDOCPOINTER);
+			_subEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_OFF);
 			_subEditView.execute(SCI_SETDOCPOINTER, 0, buf->getDocument());
+			_subEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_ON);
 			for (size_t j = 0, len = session._subViewFiles[k]._marks.size(); j < len ; ++j)
 			{
 				_subEditView.execute(SCI_MARKERADD, session._subViewFiles[k]._marks[j], MARK_BOOKMARK);
 			}
+			_subEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_OFF);
 			_subEditView.execute(SCI_SETDOCPOINTER, 0, prevDoc);
+			_subEditView.execute(SCI_SETMODEVENTMASK, MODEVENTMASK_ON);
 
 			++k;
 		}
diff --git a/PowerEditor/src/NppNotification.cpp b/PowerEditor/src/NppNotification.cpp
index 7e1ab477c..cb4ca37f7 100644
--- a/PowerEditor/src/NppNotification.cpp
+++ b/PowerEditor/src/NppNotification.cpp
@@ -443,10 +443,7 @@ BOOL Notepad_plus::notify(SCNotification *notification)
 				LPNMMOUSE lpnm = (LPNMMOUSE)notification;
 				if (lpnm->dwItemSpec == DWORD(STATUSBAR_CUR_POS))
 				{
-					bool isFirstTime = !_goToLineDlg.isCreated();
-					_goToLineDlg.doDialog(_nativeLangSpeaker.isRTL());
-					if (isFirstTime)
-						_nativeLangSpeaker.changeDlgLang(_goToLineDlg.getHSelf(), "GoToLine");
+					command(IDM_SEARCH_GOTOLINE);
 				}
 				else if (lpnm->dwItemSpec == DWORD(STATUSBAR_DOC_SIZE))
 				{
diff --git a/PowerEditor/src/ScintillaComponent/Buffer.cpp b/PowerEditor/src/ScintillaComponent/Buffer.cpp
index c6fc8d901..ef3904680 100644
--- a/PowerEditor/src/ScintillaComponent/Buffer.cpp
+++ b/PowerEditor/src/ScintillaComponent/Buffer.cpp
@@ -1391,7 +1391,9 @@ SavingStatus FileManager::saveBuffer(BufferID id, const wchar_t* filename, bool
 
 		if (isCopy) // "Save a Copy As..." command
 		{
+			_pscratchTilla->execute(SCI_SETMODEVENTMASK, MODEVENTMASK_OFF);
 			_pscratchTilla->execute(SCI_SETDOCPOINTER, 0, _scratchDocDefault);
+			_pscratchTilla->execute(SCI_SETMODEVENTMASK, MODEVENTMASK_ON);
 			return SavingStatus::SaveOK;	//all done - we don't change the current buffer's path to "fullpath", since it's "Save a Copy As..." action.
 		}
 
diff --git a/PowerEditor/src/ScintillaComponent/Buffer.h b/PowerEditor/src/ScintillaComponent/Buffer.h
index e96ec3bec..37dc845f7 100644
--- a/PowerEditor/src/ScintillaComponent/Buffer.h
+++ b/PowerEditor/src/ScintillaComponent/Buffer.h
@@ -216,6 +216,10 @@ public:
 
 	void setLangType(LangType lang, const wchar_t * userLangName = L"");
 
+	int getLastLangType() const { return _lastLangType; }
+
+	void setLastLangType(int val) { _lastLangType = val; }
+
 	UniMode getUnicodeMode() const { return _unicodeMode; }
 
 	void setUnicodeMode(UniMode mode);
@@ -388,6 +392,7 @@ private:
 	//document properties
 	Document _doc;	//invariable
 	LangType _lang = L_TEXT;
+	int _lastLangType = -1;
 	std::wstring _userLangExt; // it's useful if only (_lang == L_USER)
 	bool _isDirty = false;
 	EolType _eolFormat = EolType::osdefault;
diff --git a/PowerEditor/src/ScintillaComponent/GoToLineDlg.cpp b/PowerEditor/src/ScintillaComponent/GoToLineDlg.cpp
index 2f40c4ee7..2a8b7a27c 100644
--- a/PowerEditor/src/ScintillaComponent/GoToLineDlg.cpp
+++ b/PowerEditor/src/ScintillaComponent/GoToLineDlg.cpp
@@ -87,6 +87,7 @@ intptr_t CALLBACK GoToLineDlg::run_dlgProc(UINT message, WPARAM wParam, LPARAM l
 
 				case IDOK :
                 {
+					(*_ppEditView)->execute(SCI_SETMODEVENTMASK, MODEVENTMASK_OFF);
                     long long line = getLine();
                     if (line != -1)
                     {
@@ -111,6 +112,7 @@ intptr_t CALLBACK GoToLineDlg::run_dlgProc(UINT message, WPARAM wParam, LPARAM l
 							(*_ppEditView)->execute(SCI_GOTOPOS, posToGoto);
 						}
 					}
+					(*_ppEditView)->execute(SCI_SETMODEVENTMASK, MODEVENTMASK_ON);
 
 					SCNotification notification{};
 					notification.nmhdr.code = SCN_PAINTED;
diff --git a/PowerEditor/src/ScintillaComponent/ScintillaEditView.cpp b/PowerEditor/src/ScintillaComponent/ScintillaEditView.cpp
index 92580abc2..82b63d037 100644
--- a/PowerEditor/src/ScintillaComponent/ScintillaEditView.cpp
+++ b/PowerEditor/src/ScintillaComponent/ScintillaEditView.cpp
@@ -230,6 +230,8 @@ void ScintillaEditView::init(HINSTANCE hInst, HWND hPere)
 		throw std::runtime_error("ScintillaEditView::init : SCI_GETDIRECTPOINTER message failed");
 	}
 
+	execute(SCI_SETMODEVENTMASK, MODEVENTMASK_OFF);
+	execute(SCI_SETIDLESTYLING, SC_IDLESTYLING_ALL, 0);
 	execute(SCI_SETMARGINMASKN, _SC_MARGE_FOLDER, SC_MASK_FOLDERS);
 	showMargin(_SC_MARGE_FOLDER, true);
 
@@ -345,6 +347,7 @@ void ScintillaEditView::init(HINSTANCE hInst, HWND hPere)
 			delete[] defaultCharList;
 		}
 	}
+	execute(SCI_SETMODEVENTMASK, MODEVENTMASK_ON);
 	//Get the startup document and make a buffer for it so it can be accessed like a file
 	attachDefaultDoc();
 }
@@ -2109,6 +2112,19 @@ void ScintillaEditView::defineDocType(LangType typeDoc)
 		if (currentIndentMode != docIndentMode)
 			execute(SCI_SETINDENTATIONGUIDES, docIndentMode);
 	}
+
+	execute(SCI_SETLAYOUTCACHE, SC_CACHE_DOCUMENT, 0);
+	execute(SCI_STARTSTYLING, 0, 0);
+}
+
+Document ScintillaEditView::getBlankDocument()
+{
+	if(_blankDocument==0)
+	{
+		_blankDocument=static_cast<Document>(execute(SCI_CREATEDOCUMENT,0,SC_DOCUMENTOPTION_TEXT_LARGE));
+		execute(SCI_ADDREFDOCUMENT,0,_blankDocument);
+	}
+	return _blankDocument;
 }
 
 BufferID ScintillaEditView::attachDefaultDoc()
@@ -2278,16 +2294,51 @@ void ScintillaEditView::activateBuffer(BufferID buffer, bool force)
 	// put the state into the future ex buffer
 	_currentBuffer->setHeaderLineState(lineStateVector, this);
 
+	_prevBuffer = _currentBuffer;
+
 	_currentBufferID = buffer;	//the magical switch happens here
 	_currentBuffer = newBuf;
-	// change the doc, this operation will decrease
-	// the ref count of old current doc and increase the one of the new doc. FileManager should manage the rest
-	// Note that the actual reference in the Buffer itself is NOT decreased, Notepad_plus does that if neccessary
-	execute(SCI_SETDOCPOINTER, 0, _currentBuffer->getDocument());
 
-	// Due to execute(SCI_CLEARDOCUMENTSTYLE); in defineDocType() function
-	// defineDocType() function should be called here, but not be after the fold info loop
-	defineDocType(_currentBuffer->getLangType());
+	const bool isSameLangType = _prevBuffer != nullptr && ((_prevBuffer == _currentBuffer) || (_prevBuffer->getLangType() == _currentBuffer->getLangType()));
+	const int currentLangInt = static_cast<int>(_currentBuffer->getLangType());
+	const bool isFirstActiveBuffer = (_currentBuffer->getLastLangType() != currentLangInt);
+
+	if (isFirstActiveBuffer)  // Entering the tab for the 1st time
+	{
+		// change the doc, this operation will decrease
+		// the ref count of old current doc and increase the one of the new doc. FileManager should manage the rest
+		// Note that the actual reference in the Buffer itself is NOT decreased, Notepad_plus does that if neccessary
+		execute(SCI_SETMODEVENTMASK, MODEVENTMASK_OFF);
+		execute(SCI_SETDOCPOINTER, 0, _currentBuffer->getDocument());
+		execute(SCI_SETMODEVENTMASK, MODEVENTMASK_ON);
+
+		// Due to execute(SCI_CLEARDOCUMENTSTYLE); in defineDocType() function
+		// defineDocType() function should be called here, but not be after the fold info loop
+		defineDocType(_currentBuffer->getLangType());
+	}
+	else if (isSameLangType) // After the 2nd entering with the same language type
+	{
+		// No need to call defineDocType() since it's the same language type
+		execute(SCI_SETMODEVENTMASK, MODEVENTMASK_OFF);
+		execute(SCI_SETDOCPOINTER, 0, _currentBuffer->getDocument());
+		execute(SCI_SETMODEVENTMASK, MODEVENTMASK_ON);
+	}
+	else // Entering the tab for the 2nd or more times, with the different language type
+	{
+		// In order to improve the performance of switch-in on the 2nd or more times for the large files,
+		// a blank document is used for accelerate defineDocType() call.
+		execute(SCI_SETMODEVENTMASK, MODEVENTMASK_OFF);
+		execute(SCI_SETDOCPOINTER, 0, getBlankDocument());
+		execute(SCI_SETMODEVENTMASK, MODEVENTMASK_ON);
+
+		defineDocType(_currentBuffer->getLangType());
+
+		execute(SCI_SETMODEVENTMASK, MODEVENTMASK_OFF);
+		execute(SCI_SETDOCPOINTER, 0, _currentBuffer->getDocument());
+		execute(SCI_SETMODEVENTMASK, MODEVENTMASK_ON);
+	}
+
+	_currentBuffer->setLastLangType(currentLangInt);
 
 	setWordChars();
 
diff --git a/PowerEditor/src/ScintillaComponent/ScintillaEditView.h b/PowerEditor/src/ScintillaComponent/ScintillaEditView.h
index fadc47bc6..ae715d509 100644
--- a/PowerEditor/src/ScintillaComponent/ScintillaEditView.h
+++ b/PowerEditor/src/ScintillaComponent/ScintillaEditView.h
@@ -93,6 +93,9 @@ const bool fold_uncollapse = true;
 const bool fold_collapse = false;
 #define MAX_FOLD_COLLAPSE_LEVEL	8
 
+#define MODEVENTMASK_OFF         0
+#define MODEVENTMASK_ON          SC_MOD_DELETETEXT | SC_MOD_INSERTTEXT | SC_PERFORMED_UNDO | SC_PERFORMED_REDO | SC_MOD_CHANGEINDICATOR
+
 enum TextCase : UCHAR
 {
 	UPPERCASE,
@@ -428,6 +431,11 @@ public:
 
 	virtual void destroy()
 	{
+		if (_blankDocument != 0)
+		{
+			execute(SCI_RELEASEDOCUMENT, 0, _blankDocument);
+			_blankDocument = 0;
+		}
 		::DestroyWindow(_hSelf);
 		_hSelf = NULL;
 		_pScintillaFunc = NULL;
@@ -871,6 +879,8 @@ public:
 	bool pasteToMultiSelection() const;
 	void setElementColour(int element, COLORREF color) const { execute(SCI_SETELEMENTCOLOUR, element, color | 0xFF000000); };
 
+	Document getBlankDocument();
+
 protected:
 	static bool _SciInit;
 
@@ -894,6 +904,9 @@ protected:
 	BufferID _currentBufferID = nullptr;
 	Buffer * _currentBuffer = nullptr;
 
+	Buffer* _prevBuffer = nullptr;
+	Document _blankDocument = 0;
+
 	int _codepage = CP_ACP;
 	bool _wrapRestoreNeeded = false;
 	bool _positionRestoreNeeded = false;
diff --git a/PowerEditor/src/menuCmdID.h b/PowerEditor/src/menuCmdID.h
index eac1411e4..ad8eaaa66 100644
--- a/PowerEditor/src/menuCmdID.h
+++ b/PowerEditor/src/menuCmdID.h
@@ -582,7 +582,7 @@
     #define    IDM_FORUM            (IDM_ABOUT  + 4)
     //#define    IDM_PLUGINSHOME      (IDM_ABOUT  + 5)
     #define    IDM_UPDATE_NPP       (IDM_ABOUT  + 6)
-    #define    IDM_WIKIFAQ          (IDM_ABOUT  + 7)
+    //#define    IDM_WIKIFAQ          (IDM_ABOUT  + 7)
     //#define    IDM_HELP             (IDM_ABOUT  + 8)
     #define    IDM_CONFUPDATERPROXY (IDM_ABOUT  + 9)
     #define    IDM_CMDLINEARGUMENTS (IDM_ABOUT  + 10)