diff --git a/comdel/display/schema_display.cpp b/comdel/display/schema_display.cpp
index 80666d3..f415130 100644
--- a/comdel/display/schema_display.cpp
+++ b/comdel/display/schema_display.cpp
@@ -9,7 +9,7 @@ Schema::Schema()
 }
 
 
-void Schema::setSchema(std::optional<domain::Schema>& schema)
+void Schema::setSchema(std::optional<domain::Schema> schema)
 {
     scene.clear();
     this->schema = schema;
diff --git a/comdel/display/schema_display.h b/comdel/display/schema_display.h
index 81d680e..6acd574 100644
--- a/comdel/display/schema_display.h
+++ b/comdel/display/schema_display.h
@@ -14,7 +14,7 @@ class Schema: public QGraphicsView
 public:
     Schema();
 
-    void setSchema(std::optional<domain::Schema>& schema);
+    void setSchema(std::optional<domain::Schema> schema);
 
 private:
     QGraphicsScene scene;
diff --git a/mainwindow.cpp b/mainwindow.cpp
index b3759e1..83fb034 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -9,6 +9,8 @@
 #include <comdel/domain/schemacreator.h>
 
 #include <iostream>
+#include <QPlainTextEdit>
+#include <sstream>
 
 MainWindow::MainWindow(QWidget *parent)
     : QMainWindow(parent)
@@ -40,45 +42,60 @@ void MainWindow::setupUi()
 
     // setup central content
     libraryDisplay = new display::Library();
+
+    auto schemaParent = new QWidget();
+    auto schemaLayout = new QVBoxLayout();
+    schemaParent->setLayout(schemaLayout);
+
     schemaDisplay = new display::Schema();
+    schemaLayout->setMargin(0);
+    schemaLayout->addWidget(schemaDisplay, 1);
 
     layout->setMargin(0);
     layout->addWidget(libraryDisplay);
-    layout->addWidget(schemaDisplay, 1);
-
+    layout->addWidget(schemaParent, 1);
 
+    log = new QPlainTextEdit();
+    log->setFont(QFont("Courier"));
+    schemaLayout->addWidget(log);
 }
 
 void MainWindow::onTestModal() {
     QString filename = "/home/bbr/Documents/personal/projects/modeler/schema.csl";
 
+    std::ostringstream buffer;
+
     if(!filename.isEmpty()) {
         clear();
 
         ParseContext parseContext;
-        auto schemaNode = loadSchemaFromFile(&parseContext, filename.toStdString().c_str(), std::cout);
+        auto schemaNode = loadSchemaFromFile(&parseContext, filename.toStdString().c_str(), buffer);
 
         if(schemaNode) {
             domain::SchemaCreator generator(signatures);
             library = generator.loadLibrary(*schemaNode->library);
 
-            for (auto& error : generator.getErrors()) {
-                parseContext.formatError(error, std::cout, "GENERATOR ERROR: ");
-            }
-
             if(library) {
                 schema = generator.loadSchema(*schemaNode, *library);
-
-                for (auto& error : generator.getErrors()) {
-                    parseContext.formatError(error, std::cout, "LIBRARY ERROR: ");
-                }
             }
 
-            libraryDisplay->setLibrary(library);
-            schemaDisplay->setSchema(schema);
+            for (auto& error : generator.getErrors()) {
+                parseContext.formatError(error, buffer, "ERROR: ");
+            }
+
+            if(generator.getErrors().empty()) {
+                libraryDisplay->setLibrary(library);
+                schemaDisplay->setSchema(schema);
+            } else {
+                libraryDisplay->setLibrary(std::nullopt);
+                schemaDisplay->setSchema(std::nullopt);
+            }
+
         }
     }
 
+    log->appendPlainText(QString::fromStdString(buffer.str()));
+
 }
 
 void MainWindow::onLoadLibrary() {
@@ -131,6 +148,8 @@ void MainWindow::onLoadSchema() {
                 }
             }
 
+
+
             libraryDisplay->setLibrary(library);
             schemaDisplay->setSchema(schema);
         }
diff --git a/mainwindow.h b/mainwindow.h
index 200d0dc..c2ad269 100644
--- a/mainwindow.h
+++ b/mainwindow.h
@@ -9,6 +9,7 @@
 
 #include <comdel/domain/library.h>
 #include <comdel/domain/schema.h>
+#include <QPlainTextEdit>
 
 QT_BEGIN_NAMESPACE
 namespace Ui { class MainWindow; }
@@ -40,5 +41,6 @@ private slots:
 
 private:
     Ui::MainWindow *ui;
+    QPlainTextEdit *log;
 };
 #endif // MAIN_WINDOW_H