diff --git a/PowerEditor/src/MISC/Common/Common.cpp b/PowerEditor/src/MISC/Common/Common.cpp
index 68603951..851e0948 100644
--- a/PowerEditor/src/MISC/Common/Common.cpp
+++ b/PowerEditor/src/MISC/Common/Common.cpp
@@ -1155,7 +1155,7 @@ bool isCertificateValidated(const generic_string & fullFilePath, const generic_s
 
 		isOK = true;
 	}
-	catch (generic_string s)
+	catch (const generic_string& s)
 	{
 		// display error message
 		MessageBox(NULL, s.c_str(), TEXT("Certificate checking"), MB_OK);
diff --git a/PowerEditor/src/MISC/Common/verifySignedfile.cpp b/PowerEditor/src/MISC/Common/verifySignedfile.cpp
index aac1a9da..927462e1 100644
--- a/PowerEditor/src/MISC/Common/verifySignedfile.cpp
+++ b/PowerEditor/src/MISC/Common/verifySignedfile.cpp
@@ -57,7 +57,7 @@ SecurityGard::SecurityGard()
 	_pluginListSha256.push_back(TEXT("3ecd7f9c56bcd659a4126c659eb69b354789c78574a82390749ac751ae539bc6")); // v1.0.7 64 bit (unsigned)
 }
 
-bool SecurityGard::checkModule(std::wstring filePath, NppModule module2check)
+bool SecurityGard::checkModule(const std::wstring& filePath, NppModule module2check)
 {
 	if (_securityMode == sm_certif)
 		return verifySignedLibrary(filePath, module2check);
@@ -67,7 +67,7 @@ bool SecurityGard::checkModule(std::wstring filePath, NppModule module2check)
 		return false;
 }
 
-bool SecurityGard::checkSha256(std::wstring filePath, NppModule module2check)
+bool SecurityGard::checkSha256(const std::wstring& filePath, NppModule module2check)
 {
 	std::string content = getFileContent(filePath.c_str());
 	uint8_t sha2hash[32];
diff --git a/PowerEditor/src/MISC/Common/verifySignedfile.h b/PowerEditor/src/MISC/Common/verifySignedfile.h
index 5f1b9c8e..45994901 100644
--- a/PowerEditor/src/MISC/Common/verifySignedfile.h
+++ b/PowerEditor/src/MISC/Common/verifySignedfile.h
@@ -66,7 +66,7 @@ class SecurityGard final
 {
 public:
 	SecurityGard();
-	bool checkModule(std::wstring filePath, NppModule module2check);
+	bool checkModule(const std::wstring& filePath, NppModule module2check);
 
 private:
 	// SHA256
@@ -75,7 +75,7 @@ private:
 	std::vector<std::wstring> _gupSha256;
 	std::vector<std::wstring> _pluginListSha256;
 
-	bool checkSha256(std::wstring filePath, NppModule module2check);
+	bool checkSha256(const std::wstring& filePath, NppModule module2check);
 
 	// Code signing certificate
 	std::wstring _signer_display_name = TEXT("Notepad++");
diff --git a/PowerEditor/src/Parameters.cpp b/PowerEditor/src/Parameters.cpp
index 3660bf67..9ce6bd28 100644
--- a/PowerEditor/src/Parameters.cpp
+++ b/PowerEditor/src/Parameters.cpp
@@ -2652,7 +2652,9 @@ std::pair<unsigned char, unsigned char> NppParameters::feedUserLang(TiXmlNode *n
 					_userLangArray[_nbUserLang - 1]->_styleArray.addStyler(i, globalMappper().styleNameMapper[i].c_str());
 			}
 
-		} catch (std::exception e) {
+		}
+		catch (const std::exception& /*e*/)
+		{
 			delete _userLangArray[--_nbUserLang];
 		}
 	}
diff --git a/PowerEditor/src/ScitillaComponent/ScintillaCtrls.h b/PowerEditor/src/ScitillaComponent/ScintillaCtrls.h
index 81b4a61e..0cc6351b 100644
--- a/PowerEditor/src/ScitillaComponent/ScintillaCtrls.h
+++ b/PowerEditor/src/ScitillaComponent/ScintillaCtrls.h
@@ -48,8 +48,8 @@ public :
 	
 private:
 	std::vector<ScintillaEditView *> _scintVector;
-	HINSTANCE _hInst;
-	HWND _hParent;
+	HINSTANCE _hInst = nullptr;
+	HWND _hParent = nullptr;
 	int getIndexFrom(HWND handle2Find);
 };
 
diff --git a/PowerEditor/src/WinControls/WindowsDlg/WindowsDlg.h b/PowerEditor/src/WinControls/WindowsDlg/WindowsDlg.h
index 0c457a3a..108cb9b6 100644
--- a/PowerEditor/src/WinControls/WindowsDlg/WindowsDlg.h
+++ b/PowerEditor/src/WinControls/WindowsDlg/WindowsDlg.h
@@ -60,12 +60,6 @@ class WindowsDlg : public SizeableDlg
 {
 	typedef SizeableDlg MyBaseClass;
 
-	class CachedValue
-	{
-		generic_string fullname;
-		int index;
-	};
-
 public :
 	WindowsDlg();
 	int doDialog();
diff --git a/PowerEditor/src/WinControls/shortcut/shortcut.h b/PowerEditor/src/WinControls/shortcut/shortcut.h
index 68535a7d..065b84e0 100644
--- a/PowerEditor/src/WinControls/shortcut/shortcut.h
+++ b/PowerEditor/src/WinControls/shortcut/shortcut.h
@@ -321,7 +321,7 @@ private:
 class UserCommand : public CommandShortcut {
 friend class NppParameters;
 public:
-	UserCommand(Shortcut sc, const TCHAR *cmd, int id) : CommandShortcut(sc, id), _cmd(cmd) {_canModifyName = true;};
+	UserCommand(const Shortcut& sc, const TCHAR *cmd, int id) : CommandShortcut(sc, id), _cmd(cmd) {_canModifyName = true;};
 	const TCHAR* getCmd() const {return _cmd.c_str();};
 private:
 	generic_string _cmd;
@@ -330,7 +330,7 @@ private:
 class PluginCmdShortcut : public CommandShortcut {
 //friend class NppParameters;
 public:
-	PluginCmdShortcut(Shortcut sc, int id, const TCHAR *moduleName, unsigned short internalID) :\
+	PluginCmdShortcut(const Shortcut& sc, int id, const TCHAR *moduleName, unsigned short internalID) :\
 		CommandShortcut(sc, id), _id(id), _moduleName(moduleName), _internalID(internalID) {};
 	bool isValid() const {
 		if (!Shortcut::isValid())