diff --git a/src/dltfileindexer.cpp b/src/dltfileindexer.cpp
index f85f9a93..9013eb97 100644
--- a/src/dltfileindexer.cpp
+++ b/src/dltfileindexer.cpp
@@ -151,7 +151,6 @@ bool DltFileIndexer::index(int num)
     quint8 version=1;
     qint64 lengthOffset=2;
     qint64 storageLength=0;
-    int iPercent =0;
     errors_in_file  = 0;
     char *data = new char[DLT_FILE_INDEXER_SEG_SIZE];
 
@@ -378,7 +377,6 @@ bool DltFileIndexer::indexFilter(QStringList filenames)
 {
     QSharedPointer<QDltMsg> msg;
     QDltFilterList filterList;
-    QTime time;
     quint64 ix = 0;
     unsigned int iPercent = 0;
 
@@ -429,12 +427,6 @@ bool DltFileIndexer::indexFilter(QStringList filenames)
         return true;
     }
 
-    unsigned int modvalue = dltFile->size()/20;
-    if (modvalue == 0) // avoid divison by zero
-    {
-        modvalue = 1;
-    }
-
     // Initialise progress bar
     emit(progressText(QString("CFI %1/%2").arg(currentRun).arg(maxRun)));
     emit(progressMax(100));
@@ -470,7 +462,7 @@ bool DltFileIndexer::indexFilter(QStringList filenames)
     qDebug() << "Create filter index: Start";
 
     /* init fileprogress */
-    int progressCounter = 1;
+    unsigned int progressCounter = 1;
     emit progress(0);
 
     // Start reading messages
diff --git a/src/dltfileindexer.h b/src/dltfileindexer.h
index 3ba992bf..0951bfae 100644
--- a/src/dltfileindexer.h
+++ b/src/dltfileindexer.h
@@ -128,7 +128,7 @@ class DltFileIndexer : public QThread
     // get index of all messages
     QVector<qint64> getIndexAll() { return indexAllList; }
     QVector<qint64> getIndexFilters() { return indexFilterList; }
-    QList<int> getGetLogInfoList() { return getLogInfoList; }
+    const QList<int>& getGetLogInfoList() { return getLogInfoList; }
 
     // let worker thread append to getLogInfoList
     void appendToGetLogInfoList(int value);
diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index 100ee7da..ddf67f32 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -49,6 +49,8 @@
 #include <QTemporaryFile>
 #include <QtEndian>
 
+#include <QThreadPool>
+
 /**
  * From QDlt.
  * Must be a "C" include to interpret the imports correctly
@@ -685,8 +687,8 @@ void MainWindow::initFileHandling()
     ui->checkBoxSortByTimestamp->setEnabled(ui->filtersEnabled->isChecked());
     ui->checkBoxSortByTimestamp->setChecked(QDltSettingsManager::getInstance()->value("startup/sortByTimestampEnabled", false).toBool());
     ui->checkBoxFilterRange->setEnabled(ui->filtersEnabled->isChecked());
-    ui->lineEditFilterStart->setEnabled(ui->checkBoxFilterRange->isChecked() & ui->filtersEnabled->isChecked());
-    ui->lineEditFilterEnd->setEnabled(ui->checkBoxFilterRange->isChecked() & ui->filtersEnabled->isChecked());
+    ui->lineEditFilterStart->setEnabled(ui->checkBoxFilterRange->isChecked() && ui->filtersEnabled->isChecked());
+    ui->lineEditFilterEnd->setEnabled(ui->checkBoxFilterRange->isChecked() && ui->filtersEnabled->isChecked());
 
     /* Process Project */
     if(QDltOptManager::getInstance()->isProjectFile())
@@ -1012,6 +1014,7 @@ void MainWindow::closeEvent(QCloseEvent *event)
     settingsDlg->writeSettings(this);
     if(true == isSearchOngoing)
     {
+        qDebug() << "Ignoring close event";
         event->ignore();
     }
     else if(settings->tempCloseWithoutAsking || outputfile.size() == 0)
@@ -1895,7 +1898,7 @@ void MainWindow::on_action_menuFile_Clear_triggered()
     return;
 }
 
-void MainWindow::contextLoadingFile(QDltMsg &msg)
+void MainWindow::contextLoadingFile(const QDltMsg &msg)
 {
     /* analyse message, check if DLT control message response */
     if ( (msg.getType()==QDltMsg::DltTypeControl) && (msg.getSubtype()==QDltMsg::DltControlResponse))
@@ -1931,7 +1934,7 @@ void MainWindow::contextLoadingFile(QDltMsg &msg)
 
         }
 
-        controlMessage_ReceiveControlMessage(ecuitemFound,msg);
+        controlMessage_ReceiveControlMessage(ecuitemFound, msg);
     }
 }
 
@@ -2060,15 +2063,19 @@ void MainWindow::reloadLogFileFinishFilter()
     // process getLogInfoMessages
     if(( dltIndexer->getMode() == DltFileIndexer::modeIndexAndFilter) && settings->updateContextLoadingFile)
     {
-        QList<int> list = dltIndexer->getGetLogInfoList();
-        QDltMsg msg;
+        qDebug() << "Populating ECUs tree";
+        isSearchOngoing = true;
+        QThreadPool::globalInstance()->start([this] {
+            const QList<int>& msgIndexList = dltIndexer->getGetLogInfoList();
 
-        // FIXME: this is slow operation running in the main loop
-        for(int num=0;num<list.size();num++)
-        {
-            if(qfile.getMsg(list[num],msg))
-                contextLoadingFile(msg);
-        }
+            QDltMsg msg;
+            for (const auto msgIndex : msgIndexList) {
+                if (qfile.getMsg(msgIndex, msg))
+                    contextLoadingFile(msg);
+            }
+            isSearchOngoing = false;
+        });
+        qDebug() << "Populating ECUs end.";
     }
 
     // reconnect ecus again
@@ -4461,7 +4468,7 @@ void MainWindow::onSearchresultsTableSelectionChanged(const QItemSelection & sel
     }
 }
 
-void MainWindow::controlMessage_ReceiveControlMessage(EcuItem *ecuitem, QDltMsg &msg)
+void MainWindow::controlMessage_ReceiveControlMessage(EcuItem *ecuitem, const QDltMsg &msg)
 {
     const char *ptr;
     int32_t length;
@@ -6399,7 +6406,7 @@ void MainWindow::updatePlugin(PluginItem *item)
     }
 }
 
-void MainWindow::versionString(QDltMsg &msg)
+void MainWindow::versionString(const QDltMsg &msg)
 {
     // get the version string from the version message
     // Skip the ServiceID, Status and Length bytes and start from the String containing the ECU Software Version
diff --git a/src/mainwindow.h b/src/mainwindow.h
index 91c62be5..4abd3cd2 100644
--- a/src/mainwindow.h
+++ b/src/mainwindow.h
@@ -273,7 +273,7 @@ class MainWindow : public QMainWindow
     void controlMessage_SetTimingPackets(EcuItem* ecuitem, bool enable);
     void controlMessage_GetSoftwareVersion(EcuItem* ecuitem);
     void controlMessage_GetLogInfo(EcuItem* ecuitem);
-    void controlMessage_ReceiveControlMessage(EcuItem *ecuitem,QDltMsg &msg);
+    void controlMessage_ReceiveControlMessage(EcuItem *ecuitem, const QDltMsg &msg);
     void controlMessage_SetContext(EcuItem *ecuitem, QString apid, QString ctid,QString ctdescription,int log_level,int trace_status);
     void controlMessage_SetApplication(EcuItem *ecuitem, QString apid, QString appdescription);
     void controlMessage_Marker();
@@ -286,8 +286,8 @@ class MainWindow : public QMainWindow
     void updatePluginsECUList();
     void updatePlugins();
     void updatePlugin(PluginItem *item);
-    void contextLoadingFile(QDltMsg &msg);
-    void versionString(QDltMsg &msg);
+    void contextLoadingFile(const QDltMsg &msg);
+    void versionString(const QDltMsg &msg);
     void pluginsAutoload(QString version);
 
     void connectECU(EcuItem *ecuitem,bool force = false);
@@ -633,7 +633,6 @@ public slots:
 
 signals:
     void dltFileLoaded(const QStringList& paths);
-
 };
 
 #endif // MAINWINDOW_H