diff --git a/RedPandaIDE/HighlighterManager.cpp b/RedPandaIDE/HighlighterManager.cpp
index 70e1bc61..6307c31d 100644
--- a/RedPandaIDE/HighlighterManager.cpp
+++ b/RedPandaIDE/HighlighterManager.cpp
@@ -34,6 +34,8 @@ PSynHighlighter HighlighterManager::copyHighlighter(PSynHighlighter highlighter)
         return PSynHighlighter();
     if (highlighter->getName() == SYN_HIGHLIGHTER_CPP)
         return getCppHighlighter();
+    //todo
+    return PSynHighlighter();
 }
 
 PSynHighlighter HighlighterManager::getCppHighlighter()
diff --git a/RedPandaIDE/RedPandaIDE.pro b/RedPandaIDE/RedPandaIDE.pro
index 1940a878..8c332d52 100644
--- a/RedPandaIDE/RedPandaIDE.pro
+++ b/RedPandaIDE/RedPandaIDE.pro
@@ -15,6 +15,7 @@ SOURCES += \
     compiler/compilermanager.cpp \
     compiler/executablerunner.cpp \
     compiler/filecompiler.cpp \
+    compiler/stdincompiler.cpp \
     editor.cpp \
     editorlist.cpp \
     iconsmanager.cpp \
@@ -58,6 +59,7 @@ HEADERS += \
     compiler/compilermanager.h \
     compiler/executablerunner.h \
     compiler/filecompiler.h \
+    compiler/stdincompiler.h \
     editor.h \
     editorlist.h \
     iconsmanager.h \
diff --git a/RedPandaIDE/compiler/compiler.cpp b/RedPandaIDE/compiler/compiler.cpp
index 04e48b03..63f0ffcb 100644
--- a/RedPandaIDE/compiler/compiler.cpp
+++ b/RedPandaIDE/compiler/compiler.cpp
@@ -9,10 +9,13 @@
 #include <QDebug>
 #include <QTime>
 
-Compiler::Compiler(bool silent,bool onlyCheckSyntax):
+#define COMPILE_PROCESS_END "---//END//----"
+
+Compiler::Compiler(const QString &filename, bool silent, bool onlyCheckSyntax):
     QThread(),
     mSilent(silent),
-    mOnlyCheckSyntax(onlyCheckSyntax)
+    mOnlyCheckSyntax(onlyCheckSyntax),
+    mFilename(filename)
 {
 
 }
@@ -26,8 +29,7 @@ void Compiler::run()
             mWarningCount = 0;
             QElapsedTimer timer;
             timer.start();
-            runCommand(mCompiler, mArguments, QFileInfo(mCompiler).absolutePath());
-
+            runCommand(mCompiler, mArguments, QFileInfo(mCompiler).absolutePath(), pipedText());
             log("");
             log(tr("Compile Result:"));
             log("------------------");
@@ -62,9 +64,10 @@ QString Compiler::getFileNameFromOutputLine(QString &line) {
         temp = line.mid(0,pos);
         line.remove(0,pos+1);
         line=line.trimmed();
-//        if (temp.compare("<stdin>", Qt::CaseInsensitive)!=0 && !QFile(temp).exists()) {
-//            continue;
-//        }
+        if (temp.compare("<stdin>", Qt::CaseInsensitive)==0 ) {
+            temp = mFilename;
+            break;
+        }
 
         if (QFileInfo(temp).fileName() == QLatin1String("ld.exe")) { // skip ld.exe
             continue;
@@ -137,6 +140,13 @@ CompileIssueType Compiler::getIssueTypeFromOutputLine(QString &line)
 
 void Compiler::processOutput(QString &line)
 {
+    if (line == COMPILE_PROCESS_END) {
+        if (mLastIssue) {
+            emit compileIssue(mLastIssue);
+            mLastIssue.reset();
+        }
+        return;
+    }
     QString inFilePrefix = QString("In file included from ");
     QString fromPrefix = QString("from ");
     PCompileIssue issue = std::make_shared<CompileIssue>();
@@ -362,11 +372,14 @@ void Compiler::runCommand(const QString &cmd, const QString  &arguments, const Q
     process.connect(&process, &QProcess::readyReadStandardOutput,[&process,this](){
         this->log(QString::fromLocal8Bit( process.readAllStandardOutput()));
     });
+    process.connect(&process, QOverload<int, QProcess::ExitStatus>::of(&QProcess::finished),[&process,this](){
+        this->error(COMPILE_PROCESS_END);
+    });
     process.start();
-    if (!inputText.isEmpty())
-        process.write(inputText.toUtf8());
-    process.closeWriteChannel();
     process.waitForStarted(5000);
+    if (!inputText.isEmpty())
+        process.write(inputText.toLocal8Bit());
+    process.closeWriteChannel();
     while (true) {
         process.waitForFinished(1000);
         if (process.state()!=QProcess::Running) {
@@ -407,7 +420,8 @@ void Compiler::log(const QString &msg)
 
 void Compiler::error(const QString &msg)
 {
-    emit compileOutput(msg);
+    if (msg != COMPILE_PROCESS_END)
+        emit compileOutput(msg);
     for (QString& s:msg.split("\n")) {
         if (!s.isEmpty())
             processOutput(s);
diff --git a/RedPandaIDE/compiler/compiler.h b/RedPandaIDE/compiler/compiler.h
index 3d3fd33b..f7313584 100644
--- a/RedPandaIDE/compiler/compiler.h
+++ b/RedPandaIDE/compiler/compiler.h
@@ -16,7 +16,7 @@ public:
         Project,
         StdIn
     };
-    Compiler(bool silent,bool onlyCheckSyntax);
+    Compiler(const QString& filename, bool silent,bool onlyCheckSyntax);
 
 signals:
     void compileStarted();
@@ -38,6 +38,7 @@ protected:
 protected:
     virtual Settings::PCompilerSet compilerSet() = 0;
     virtual bool prepareForCompile() = 0;
+    virtual QString pipedText() = 0;
     virtual QString getCharsetArgument(const QByteArray& encoding);
     virtual QString getCCompileArguments(bool checkSyntax);
     virtual QString getCppCompileArguments(bool checkSyntax);
@@ -57,6 +58,7 @@ protected:
     int mErrorCount;
     int mWarningCount;
     PCompileIssue mLastIssue;
+    QString mFilename;
 
 private:
     bool mStop;
diff --git a/RedPandaIDE/compiler/compilermanager.cpp b/RedPandaIDE/compiler/compilermanager.cpp
index b340f2ec..f56572b0 100644
--- a/RedPandaIDE/compiler/compilermanager.cpp
+++ b/RedPandaIDE/compiler/compilermanager.cpp
@@ -1,5 +1,6 @@
 #include "compilermanager.h"
 #include "filecompiler.h"
+#include "stdincompiler.h"
 #include <QDebug>
 #include "../mainwindow.h"
 #include "executablerunner.h"
@@ -41,6 +42,23 @@ void CompilerManager::compile(const QString& filename, const QByteArray& encodin
     mCompiler->start();
 }
 
+void CompilerManager::checkSyntax(const QString &filename, const QString &content)
+{
+    QMutexLocker locker(&backgroundSyntaxChekMutex);
+    if (mBackgroundSyntaxChecker!=nullptr) {
+        return;
+    }
+    mSyntaxCheckErrorCount = 0;
+    mBackgroundSyntaxChecker = new StdinCompiler(filename,content,true,true);
+    connect(mBackgroundSyntaxChecker, &Compiler::compileFinished, this ,&CompilerManager::onSyntaxCheckFinished);
+    connect(mBackgroundSyntaxChecker, &Compiler::compileIssue, this, &CompilerManager::onSyntaxCheckIssue);
+    connect(mBackgroundSyntaxChecker, &Compiler::compileFinished, pMainWindow, &MainWindow::onCompileFinished);
+    connect(mBackgroundSyntaxChecker, &Compiler::compileOutput, pMainWindow, &MainWindow::onCompileLog);
+    connect(mBackgroundSyntaxChecker, &Compiler::compileIssue, pMainWindow, &MainWindow::onCompileIssue);
+    connect(mBackgroundSyntaxChecker, &Compiler::compileErrorOccured, pMainWindow, &MainWindow::onCompileErrorOccured);
+    mBackgroundSyntaxChecker->start();
+}
+
 void CompilerManager::run(const QString &filename, const QString &arguments, const QString &workDir)
 {
     QMutexLocker locker(&runnerMutex);
@@ -81,6 +99,18 @@ void CompilerManager::onCompileIssue(PCompileIssue)
     mCompileErrorCount ++;
 }
 
+void CompilerManager::onSyntaxCheckFinished()
+{
+    QMutexLocker locker(&backgroundSyntaxChekMutex);
+    delete mBackgroundSyntaxChecker;
+    mBackgroundSyntaxChecker=nullptr;
+}
+
+void CompilerManager::onSyntaxCheckIssue(PCompileIssue)
+{
+    mSyntaxCheckErrorCount++;
+}
+
 int CompilerManager::syntaxCheckErrorCount() const
 {
     return mSyntaxCheckErrorCount;
diff --git a/RedPandaIDE/compiler/compilermanager.h b/RedPandaIDE/compiler/compilermanager.h
index e75269a7..e41d3d7d 100644
--- a/RedPandaIDE/compiler/compilermanager.h
+++ b/RedPandaIDE/compiler/compilermanager.h
@@ -18,6 +18,7 @@ public:
     bool backgroundSyntaxChecking();
 
     void compile(const QString& filename, const QByteArray& encoding, bool silent=false,bool onlyCheckSyntax=false);
+    void checkSyntax(const QString&filename, const QString& content);
     void run(const QString& filename, const QString& arguments, const QString& workDir);
     bool canCompile(const QString& filename);
     int compileErrorCount() const;
@@ -25,9 +26,11 @@ public:
     int syntaxCheckErrorCount() const;
 
 private slots:
-    void onCompileFinished();
     void onRunnerTerminated();
+    void onCompileFinished();
     void onCompileIssue(PCompileIssue issue);
+    void onSyntaxCheckFinished();
+    void onSyntaxCheckIssue(PCompileIssue issue);
 
 private:
     Compiler* mCompiler;
diff --git a/RedPandaIDE/compiler/filecompiler.cpp b/RedPandaIDE/compiler/filecompiler.cpp
index 8b055ece..2d614bdc 100644
--- a/RedPandaIDE/compiler/filecompiler.cpp
+++ b/RedPandaIDE/compiler/filecompiler.cpp
@@ -9,8 +9,7 @@
 
 
 FileCompiler::FileCompiler(const QString &filename, const QByteArray &encoding,bool silent,bool onlyCheckSyntax):
-    Compiler(silent,onlyCheckSyntax),
-    mFileName(filename),
+    Compiler(filename, silent,onlyCheckSyntax),
     mEncoding(encoding)
 {
 
@@ -25,13 +24,13 @@ bool FileCompiler::prepareForCompile()
 {
     log(tr("Compiling single file..."));
     log("------------------");
-    log(tr("- Filename: %1").arg(mFileName));
+    log(tr("- Filename: %1").arg(mFilename));
     log(tr("- Compiler Set Name: %1").arg(compilerSet()->name()));
     log("");
-    FileType fileType = getFileType(mFileName);
-    mArguments= QString(" \"%1\"").arg(mFileName);
+    FileType fileType = getFileType(mFilename);
+    mArguments= QString(" \"%1\"").arg(mFilename);
     if (!mOnlyCheckSyntax) {
-        mOutputFile = getCompiledExecutableName(mFileName);
+        mOutputFile = getCompiledExecutableName(mFilename);
         mArguments+=QString(" -o \"%1\"").arg(mOutputFile);
 
         //remove the old file it exists
@@ -60,7 +59,7 @@ bool FileCompiler::prepareForCompile()
         mCompiler = compilerSet()->cppCompiler();
         break;
     default:
-        throw CompileError(tr("Can't find the compiler for file %1").arg(mFileName));
+        throw CompileError(tr("Can't find the compiler for file %1").arg(mFilename));
     }
     mArguments += getLibraryArguments();
 
@@ -74,3 +73,8 @@ bool FileCompiler::prepareForCompile()
     log(tr("Command: %1 %2").arg(QFileInfo(mCompiler).fileName()).arg(mArguments));
     return true;
 }
+
+QString FileCompiler::pipedText()
+{
+    return QString();
+}
diff --git a/RedPandaIDE/compiler/filecompiler.h b/RedPandaIDE/compiler/filecompiler.h
index dfb3bf36..faa6230c 100644
--- a/RedPandaIDE/compiler/filecompiler.h
+++ b/RedPandaIDE/compiler/filecompiler.h
@@ -15,9 +15,11 @@ protected:
     bool prepareForCompile() override;
 
 private:
-    QString mFileName;
     QByteArray mEncoding;
 
+    // Compiler interface
+protected:
+    QString pipedText();
 };
 
 #endif // FILECOMPILER_H
diff --git a/RedPandaIDE/compiler/stdincompiler.cpp b/RedPandaIDE/compiler/stdincompiler.cpp
new file mode 100644
index 00000000..d58985e5
--- /dev/null
+++ b/RedPandaIDE/compiler/stdincompiler.cpp
@@ -0,0 +1,63 @@
+#include "stdincompiler.h"
+#include "compilermanager.h"
+#include <QFile>
+#include <QFileInfo>
+
+StdinCompiler::StdinCompiler(const QString &filename, const QString& content, bool silent, bool onlyCheckSyntax):
+    Compiler(filename,silent,onlyCheckSyntax),
+    mContent(content)
+{
+
+}
+
+Settings::PCompilerSet StdinCompiler::compilerSet()
+{
+    return pSettings->compilerSets().defaultSet();
+}
+
+bool StdinCompiler::prepareForCompile()
+{
+    log(tr("Checking file syntax..."));
+    log("------------------");
+    log(tr("- Filename: %1").arg(mFilename));
+    log(tr("- Compiler Set Name: %1").arg(compilerSet()->name()));
+    log("");
+    FileType fileType = getFileType(mFilename);
+    if (fileType == FileType::Other)
+        fileType = FileType::CppSource;
+    QString strFileType;
+    switch(fileType) {
+    case FileType::CSource:
+        mArguments += " -x c - ";
+        mArguments += getCCompileArguments(mOnlyCheckSyntax);
+        mArguments += getCIncludeArguments();
+        strFileType = "C";
+        mCompiler = compilerSet()->CCompiler();
+        break;
+    case FileType::CppSource:
+        mArguments += " -x c++ - ";
+        mArguments += getCCompileArguments(mOnlyCheckSyntax);
+        mArguments += getCIncludeArguments();
+        strFileType = "C++";
+        mCompiler = compilerSet()->cppCompiler();
+        break;
+    default:
+        throw CompileError(tr("Can't find the compiler for file %1").arg(mFilename));
+    }
+    mArguments += getLibraryArguments();
+
+    if (!QFile(mCompiler).exists()) {
+        throw CompileError(tr("The Compiler '%1' doesn't exists!").arg(mCompiler));
+    }
+
+    log(tr("Processing %1 source file:").arg(strFileType));
+    log("------------------");
+    log(tr("%1 Compiler: %2").arg(strFileType).arg(mCompiler));
+    log(tr("Command: %1 %2").arg(QFileInfo(mCompiler).fileName()).arg(mArguments));
+    return true;
+}
+
+QString StdinCompiler::pipedText()
+{
+    return mContent;
+}
diff --git a/RedPandaIDE/compiler/stdincompiler.h b/RedPandaIDE/compiler/stdincompiler.h
new file mode 100644
index 00000000..7d31146f
--- /dev/null
+++ b/RedPandaIDE/compiler/stdincompiler.h
@@ -0,0 +1,26 @@
+#ifndef STDINCOMPILER_H
+#define STDINCOMPILER_H
+
+#include "compiler.h"
+
+class StdinCompiler : public Compiler
+{
+    Q_OBJECT
+
+public:
+    explicit StdinCompiler(const QString& filename, const QString& content, bool silent,bool onlyCheckSyntax);
+
+    // Compiler interface
+protected:
+    Settings::PCompilerSet compilerSet() override;
+    bool prepareForCompile() override;
+
+private:
+    QString mContent;
+
+    // Compiler interface
+protected:
+    QString pipedText();
+};
+
+#endif // STDINCOMPILER_H
diff --git a/RedPandaIDE/editor.cpp b/RedPandaIDE/editor.cpp
index c308077e..6f46d5be 100644
--- a/RedPandaIDE/editor.cpp
+++ b/RedPandaIDE/editor.cpp
@@ -57,7 +57,8 @@ Editor::Editor(QWidget *parent, const QString& filename,
   mInProject(inProject),
   mIsNew(isNew),
   mSyntaxErrorColor(QColorConstants::Red),
-  mSyntaxWaringColor("orange")
+  mSyntaxWaringColor("orange"),
+  mLineCount(0)
 {
     if (mFilename.isEmpty()) {
         newfileCount++;
@@ -631,6 +632,11 @@ void Editor::onModificationChanged(bool) {
 
 void Editor::onStatusChanged(SynStatusChanges changes)
 {
+    if (!changes.testFlag(SynStatusChange::scOpenFile) && (lines()->count()!=mLineCount)
+            && (lines()->count()!=0) && ((mLineCount>0) || (lines()->count()>1))) {
+        pMainWindow->checkSyntaxInBack(this);
+    }
+    mLineCount = lines()->count();
 //    if (not (scOpenFile in Changes)) and  (fText.Lines.Count <> fLineCount)
 //      and (fText.Lines.Count <> 0) and ((fLineCount>0) or (fText.Lines.Count>1)) then begin
 //      if devCodeCompletion.Enabled
diff --git a/RedPandaIDE/editor.h b/RedPandaIDE/editor.h
index b44894d4..c3ba1430 100644
--- a/RedPandaIDE/editor.h
+++ b/RedPandaIDE/editor.h
@@ -144,6 +144,7 @@ private:
     QColor mSyntaxErrorColor;
     QColor mSyntaxWaringColor;
     int mSyntaxErrorLine;
+    int mLineCount;
 
     // QWidget interface
 protected:
diff --git a/RedPandaIDE/editorlist.cpp b/RedPandaIDE/editorlist.cpp
index 55145e51..5495ede0 100644
--- a/RedPandaIDE/editorlist.cpp
+++ b/RedPandaIDE/editorlist.cpp
@@ -135,12 +135,12 @@ bool EditorList::isFileOpened(const QString &name)
     QString filename = fileInfo.absoluteFilePath();
     for (int i=0;i<mLeftPageWidget->count();i++) {
         Editor* e = static_cast<Editor*>(mLeftPageWidget->widget(i));
-        if (e->filename().compare(filename)==0)
+        if (e->filename().compare(filename)==0 || e->filename().compare(name)==0)
             return true;
     }
     for (int i=0;i<mRightPageWidget->count();i++) {
         Editor* e = static_cast<Editor*>(mRightPageWidget->widget(i));
-        if (e->filename().compare(filename)==0)
+        if (e->filename().compare(filename)==0 || e->filename().compare(name)==0)
             return true;
     }
     return false;
@@ -171,13 +171,13 @@ Editor* EditorList::getOpenedEditorByFilename(const QString &filename)
     QString fullname = fileInfo.absoluteFilePath();
     for (int i=0;i<mLeftPageWidget->count();i++) {
         Editor* e = static_cast<Editor*>(mLeftPageWidget->widget(i));
-        if (e->filename() == fullname) {
+        if (e->filename().compare(filename)==0 || e->filename().compare(fullname)==0) {
             return e;
         }
     }
     for (int i=0;i<mRightPageWidget->count();i++) {
         Editor* e = static_cast<Editor*>(mRightPageWidget->widget(i));
-        if (e->filename() == fullname) {
+        if (e->filename().compare(filename)==0 || e->filename().compare(fullname)==0) {
             return e;
         }
     }
@@ -186,15 +186,15 @@ Editor* EditorList::getOpenedEditorByFilename(const QString &filename)
 
 Editor *EditorList::getEditorByFilename(const QString &filename)
 {
-    QFileInfo fileInfo(filename);
-    QString fullname = fileInfo.absoluteFilePath();
     //check if an editor is already openned
-    Editor* e=getOpenedEditorByFilename(fullname);
+    Editor* e=getOpenedEditorByFilename(filename);
     if (e!=nullptr)
         return e;
     //Todo: check if is in the project
 
     //Create a new editor
+    QFileInfo fileInfo(filename);
+    QString fullname = fileInfo.absoluteFilePath();
     if (fileInfo.exists())
         return newEditor(fullname,ENCODING_AUTO_DETECT,false,false);
     return nullptr;
diff --git a/RedPandaIDE/mainwindow.cpp b/RedPandaIDE/mainwindow.cpp
index a8b09654..304d0386 100644
--- a/RedPandaIDE/mainwindow.cpp
+++ b/RedPandaIDE/mainwindow.cpp
@@ -4,6 +4,7 @@
 #include "editor.h"
 #include "systemconsts.h"
 #include "settings.h"
+#include "qsynedit/Constants.h"
 
 #include <QCloseEvent>
 #include <QComboBox>
@@ -47,6 +48,7 @@ MainWindow::MainWindow(QWidget *parent)
     ui->EditorTabsRight->setVisible(false);
 
     mCompilerSet = new QComboBox();
+    mCompilerSet->setMinimumWidth(200);
     ui->toolbarCompilerSet->addWidget(mCompilerSet);
     connect(mCompilerSet,QOverload<int>::of(&QComboBox::currentIndexChanged),
             this, &MainWindow::onCompilerSetChanged);
@@ -255,6 +257,45 @@ void MainWindow::updateCompilerSet()
     mCompilerSet->setCurrentIndex(index);
 }
 
+void MainWindow::checkSyntaxInBack(Editor *e)
+{
+    if (e==nullptr)
+        return;
+
+//    if not devEditor.AutoCheckSyntax then
+//      Exit;
+    //not c or cpp file
+    if (!e->highlighter() || e->highlighter()->getName()!=SYN_HIGHLIGHTER_CPP)
+        return;
+    if (mCompilerManager->backgroundSyntaxChecking())
+        return;
+    if (mCompilerManager->compiling())
+        return;
+//    if not Assigned(devCompilerSets.CompilationSet) then
+//      Exit;
+//    if fCompiler.Compiling then
+//      Exit;
+//    if fSyntaxChecker.Compiling then
+//      Exit;
+    if (mCheckSyntaxInBack)
+        return;
+
+    mCheckSyntaxInBack=true;
+    e->clearSyntaxIssues();
+    ui->tableIssues->clearIssues();
+    mCompilerManager->checkSyntax(e->filename(),e->lines()->text());
+//    if not PrepareForCompile(cttStdin,True) then begin
+//      fCheckSyntaxInBack:=False;
+//      Exit;
+//    end;
+//    if e.InProject then begin
+//      if not assigned(MainForm.fProject) then
+//        Exit;
+//      fSyntaxChecker.Project := MainForm.fProject;
+//    end;
+//    fSyntaxChecker.CheckSyntax(True);
+}
+
 void MainWindow::openCloseMessageSheet(bool open)
 {
 //    if Assigned(fReportToolWindow) then
@@ -436,8 +477,7 @@ void MainWindow::onCompileFinished()
 
     Editor * e = mEditorList->getEditor();
     if (e!=nullptr) {
-        e->beginUpdate();
-        e->endUpdate();
+        e->invalidate();
     }
 
     // Jump to problem location, sorted by significance
@@ -490,6 +530,7 @@ void MainWindow::on_actionCompile_triggered()
 {
     Editor * editor = mEditorList->getEditor();
     if (editor != NULL ) {
+        editor->clearSyntaxIssues();
         ui->tableIssues->clearIssues();
         mCompilerManager->compile(editor->filename(),editor->fileEncoding());
     }
diff --git a/RedPandaIDE/mainwindow.h b/RedPandaIDE/mainwindow.h
index 35b84f0a..4e10cc22 100644
--- a/RedPandaIDE/mainwindow.h
+++ b/RedPandaIDE/mainwindow.h
@@ -4,7 +4,6 @@
 #include <QMainWindow>
 #include "common.h"
 
-
 QT_BEGIN_NAMESPACE
 namespace Ui { class MainWindow; }
 QT_END_NAMESPACE
@@ -13,6 +12,7 @@ class EditorList;
 class QLabel;
 class QComboBox;
 class CompilerManager;
+class Editor;
 
 class MainWindow : public QMainWindow
 {
@@ -28,6 +28,8 @@ public:
     void updateEditorSettings();
     void updateEditorActions();
     void updateEditorColorSchemes();
+    void updateCompilerSet();
+    void checkSyntaxInBack(Editor* e);
 
     void applySettings();
 
@@ -102,8 +104,6 @@ public slots:
 
 private:
     void setupActions();
-
-    void updateCompilerSet();
     void openCloseMessageSheet(bool open);
 
 private:
diff --git a/RedPandaIDE/qsynedit/MiscProcs.cpp b/RedPandaIDE/qsynedit/MiscProcs.cpp
index 09d66281..dd6ce151 100644
--- a/RedPandaIDE/qsynedit/MiscProcs.cpp
+++ b/RedPandaIDE/qsynedit/MiscProcs.cpp
@@ -540,6 +540,7 @@ SynFontStyles getFontStyles(const QFont &font)
     styles.setFlag(SynFontStyle::fsItalic, font.italic());
     styles.setFlag(SynFontStyle::fsUnderline, font.underline());
     styles.setFlag(SynFontStyle::fsStrikeOut, font.strikeOut());
+    return styles;
 }
 
 bool isWordChar(const QChar& ch) {
diff --git a/RedPandaIDE/settings.cpp b/RedPandaIDE/settings.cpp
index 1f90dadb..aac95cb5 100644
--- a/RedPandaIDE/settings.cpp
+++ b/RedPandaIDE/settings.cpp
@@ -1860,6 +1860,9 @@ void Settings::CompilerSets::saveSets()
     for (int i=0;i<mList.size();i++) {
         saveSet(i);
     }
+    if (mDefaultIndex>=mList.size()) {
+        mDefaultIndex = mList.size()-1;
+    }
     mSettings->mSettings.beginGroup(SETTING_COMPILTER_SETS);
     mSettings->mSettings.setValue(SETTING_COMPILTER_SETS_DEFAULT_INDEX,mDefaultIndex);
     mSettings->mSettings.setValue(SETTING_COMPILTER_SETS_COUNT,mList.size());
@@ -1888,8 +1891,7 @@ void Settings::CompilerSets::loadSets()
                                      +"<br /><br />"
                                      +msg
                                      +"Would you like Dev-C++ to remove them for you and add the default paths to the valid paths?<br /><br />Leaving those directories will lead to problems during compilation.<br /><br />Unless you know exactly what you're doing, it is recommended that you click Yes.",
-                                     QMessageBox::Yes | QMessageBox::No) == QMessageBox::Ok) {
-                clearSets();
+                                     QMessageBox::Yes | QMessageBox::No) == QMessageBox::Yes) {
                 findSets();
                 saveSets();
                 if ( mList.size() <= mDefaultIndex)
diff --git a/RedPandaIDE/settingsdialog/compilersetoptionwidget.cpp b/RedPandaIDE/settingsdialog/compilersetoptionwidget.cpp
index 52b90a7a..71fe503c 100644
--- a/RedPandaIDE/settingsdialog/compilersetoptionwidget.cpp
+++ b/RedPandaIDE/settingsdialog/compilersetoptionwidget.cpp
@@ -139,6 +139,7 @@ void CompilerSetOptionWidget::doSave()
         saveCurrentCompilerSet();
     }
     pSettings->compilerSets().saveSets();
+    pMainWindow->updateCompilerSet();
 }
 
 void CompilerSetOptionWidget::on_cbCompilerSet_currentIndexChanged(int index)
@@ -219,6 +220,7 @@ void CompilerSetOptionWidget::on_btnFindCompilers_pressed()
     pSettings->compilerSets().clearSets();
     pSettings->compilerSets().findSets();
     doLoad();
+    setSettingsChanged();
     if (pSettings->compilerSets().size()==0) {
         QMessageBox::warning(this,tr("Failed"),tr("Can't find any compiler."));
     }