diff --git a/FinalProject/sceneviewer.cpp b/FinalProject/sceneviewer.cpp
index 7542a81..b809aa4 100644
--- a/FinalProject/sceneviewer.cpp
+++ b/FinalProject/sceneviewer.cpp
@@ -72,7 +72,7 @@ void SceneViewer::initializeGL() {
 }
 
 void SceneViewer::resizeGL(int w, int h) {
-    
+    glViewport(0, 0, w, h);
 }
 
 void SceneViewer::paintGL() {
diff --git a/FinalProject/shader.h b/FinalProject/shader.h
index ed6fa69..dff363d 100644
--- a/FinalProject/shader.h
+++ b/FinalProject/shader.h
@@ -103,6 +103,7 @@ inline void ShaderProgram::unbind() const {
 }
 
 inline void ShaderProgram::dispose() {
+    if (_programId == 0) return;
     OPENGL_EXTRA_FUNCTIONS->glDeleteProgram(_programId);
     _programId = 0;
 }
@@ -110,5 +111,8 @@ inline void ShaderProgram::dispose() {
 inline void ShaderProgram::ensureInitialized() {
     if (_programId == 0) {
         _programId = OPENGL_EXTRA_FUNCTIONS->glCreateProgram();
+        if (_programId == 0) {
+            Logger::error("Failed to create a ShaderProgram");
+        }
     }
 }
diff --git a/FinalProject/vao.h b/FinalProject/vao.h
index 33d19e3..adf93f1 100644
--- a/FinalProject/vao.h
+++ b/FinalProject/vao.h
@@ -52,6 +52,7 @@ inline void VertexArrayObject::unbind() const {
 }
 
 inline void VertexArrayObject::dispose() {
+    if (_id == 0) return;
     OPENGL_EXTRA_FUNCTIONS->glDeleteVertexArrays(1, &_id);
     _id = 0;
 }