still cannot read, but printing proper error message

App/main.cpp

@@ -33,7 +33,7 @@ void custom_terminate_handler()
     try {
         std::rethrow_exception(std::current_exception());
     } catch (const std::exception& ex) {
-        std::cerr << "terminate called after throwing an instance of 'std::runtime_error'\n"
+        std::cerr << "terminate called after throwing a std exception'\n"
                   << "what():" << std::endl;
         std::cerr << ex.what() << std::endl;
 

GUI/View/Instrument/InstrumentsQListView.cpp

@@ -13,6 +13,7 @@
 //  ************************************************************************************************
 
 #include "GUI/View/Instrument/InstrumentsQListView.h"
+#include "Base/Util/Assert.h"
 #include "GUI/Model/Device/InstrumentLibrary.h"
 #include "GUI/Model/Project/ProjectDocument.h"
 #include "GUI/View/Instrument/InstrumentLibraryDialog.h"
@@ -20,20 +21,20 @@
 #include "GUI/View/Setup/FrameActions.h"
 #include "GUI/View/Tool/Globals.h"
 #include <QFile>
-#include <QMessageBox>
 #include <QVBoxLayout>
 
 #include "GUI/Model/Descriptor/SelectionProperty.h"
-#include "GUI/Model/Device/InstrumentItems.h"
 #include "GUI/Model/Device/InstrumentItemCatalog.h"
+#include "GUI/Model/Device/InstrumentItems.h"
 #include "GUI/Support/XML/UtilXML.h"
+#include <QMessageBox>
 
 namespace {
 
 const QString XML_ROOT_TAG = "BornAgain::Instrument";
 const QString XML_VERSION_TAG = "Version";
 
-}
+} // namespace
 
 InstrumentsQListView::InstrumentsQListView()
     : m_instrument_library(std::make_unique<InstrumentLibrary>())
@@ -162,7 +163,7 @@ void InstrumentsQListView::onCopy()
 
 void InstrumentsQListView::onStoreInLibrary()
 {
-    //InstrumentLibraryDialog dlg(GUI::Global::mainWindow, m_instrument_library.get());
+    // InstrumentLibraryDialog dlg(GUI::Global::mainWindow, m_instrument_library.get());
 
     QFile file("/tmp/instrument.xml");
     if (!file.open(QFile::ReadWrite | QIODevice::Truncate | QFile::Text))
@@ -191,35 +192,51 @@ void InstrumentsQListView::onStoreInLibrary()
 
 void InstrumentsQListView::onLoadFromLibrary()
 {
+    InstrumentItem* ii = nullptr;
+
     QFile file("/tmp/instrument.xml");
-    if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
-        throw std::runtime_error("Cannot open instrument file for reading");
-
-    /*
-    InstrumentItem ii;
-
-    QXmlStreamReader r(&file);
-
-    while (!r.atEnd()) {
-        r.readNext();
-        if (r.isStartElement()) {
-            if (r.name() == XML_ROOT_TAG) {
-                const int foundVersion =
-                    r.attributes().value(XML_VERSION_TAG).toString().toInt();
-                if (foundVersion != 1)
-                    throw std::runtime_error("Unsupported version of instrument file");
-
-                ii.readFrom(&r);
-            }
-        }
+
+    try {
+	if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
+	    throw std::runtime_error("Cannot open instrument file for reading");
+	QXmlStreamReader r(&file);
+	while (!r.atEnd()) {
+	    r.readNext();
+	    if (r.isStartElement()) {
+		if (r.name() == XML_ROOT_TAG) {
+		    const int foundVersion = r.attributes().value(XML_VERSION_TAG).toString().toInt();
+		    if (foundVersion != 1)
+			throw std::runtime_error("Unsupported version of instrument file");
+
+		    const uint selection_version =
+			XML::readUIntAttribute(&r, XML::Attrib::selection_version);
+		    if (selection_version != 2)
+			throw std::runtime_error("Unsupported version of instrument stance");
+
+		    const uint typeIndex = XML::readUIntAttribute(&r, XML::Attrib::type);
+		    const auto type = static_cast<typename InstrumentItemCatalog::Type>(typeIndex);
+		    ii = InstrumentItemCatalog::create(type);
+		    ASSERT(ii);
+		    ii->readFrom(&r);
+		}
+	    }
+	}
+	if (r.hasError())
+	    throw std::runtime_error(QString("Error in instrument file, line %1, column %2: %3")
+                                     .arg(r.lineNumber())
+                                     .arg(r.columnNumber())
+                                     .arg(r.errorString())
+                                     .toStdString());
+	file.close();
+    } catch (const std::exception& ex) {
+        QMessageBox msgbox(QMessageBox::Warning, "BornAgain: failed import", QString(ex.what()),
+                           QMessageBox::Ok, nullptr);
+        msgbox.exec();
+	return;
     }
-    if (r.hasError())
-        throw std::runtime_error("Error while reading instrument file");
-    QModelIndex idx = m_model->copyInstrument(&ii);
-    selectionModel()->select(idx, QItemSelectionModel::ClearAndSelect);
-    */
-    file.close();
 
+    QModelIndex idx = m_model->copyInstrument(ii);
+    selectionModel()->select(idx, QItemSelectionModel::ClearAndSelect);
 }
 
 void InstrumentsQListView::updateActions()