diff --git a/MantidPlot/src/Mantid/MantidMatrix.cpp b/MantidPlot/src/Mantid/MantidMatrix.cpp
index 7f70a5f3b103dcad1f6c4790754e9aaeacb418e8..4366ad4dde00e23ae3ca59a52821151cb89394d2 100644
--- a/MantidPlot/src/Mantid/MantidMatrix.cpp
+++ b/MantidPlot/src/Mantid/MantidMatrix.cpp
@@ -1292,21 +1292,19 @@ void MantidMatrix::setupNewExtension(MantidMatrixModel::Type type) {
   // We need to hook up the extension
   extension.model = new MantidMatrixModel(this, m_workspace.get(), m_rows,
                                           m_cols, m_startRow, type);
-  extension.tableView = new QTableView();
-
-  // Add it to the extension collection, so we can set it up in place
-  m_extensions.emplace(type, extension);
-  auto mapped_extension = m_extensions[type];
+  extension.tableView = Mantid::Kernel::make_unique<QTableView>();
 
   // Add a new tab
-  m_tabs->insertTab(modelTypeToInt(type), mapped_extension.tableView,
-                    mapped_extension.label);
+  m_tabs->insertTab(modelTypeToInt(type), extension.tableView.get(),
+                    extension.label);
 
   // Install the eventfilter
-  mapped_extension.tableView->installEventFilter(this);
+  extension.tableView->installEventFilter(this);
 
   // Connect Table View
-  connectTableView(mapped_extension.tableView, mapped_extension.model);
+  connectTableView(extension.tableView.get(), extension.model);
+
+  m_extensions.emplace(type, std::move(extension));
 
   // Set the column width
   auto columnWidth = m_extensionRequest.getColumnWidthPreference(
@@ -1326,11 +1324,24 @@ void MantidMatrix::setupNewExtension(MantidMatrixModel::Type type) {
  * @param ws: the new workspace
  */
 void MantidMatrix::updateExtensions(Mantid::API::MatrixWorkspace_sptr ws) {
-  // Remove the tabs
-  for (auto it = m_extensions.begin(); it != m_extensions.end(); ++it) {
-    auto &extension = it->second;
-    extension.model = new MantidMatrixModel(this, ws.get(), m_rows, m_cols,
-                                            m_startRow, it->first);
-    connectTableView(extension.tableView, extension.model);
+  auto it = m_extensions.begin();
+  while (it != m_extensions.cend()) {
+    switch (it->first) {
+    case MantidMatrixModel::DX:
+      if (ws->hasDx(0)) {
+        auto &extension = it->second;
+        extension.model = new MantidMatrixModel(this, ws.get(), m_rows, m_cols,
+                                                m_startRow, it->first);
+        connectTableView(extension.tableView.get(), extension.model);
+        ++it;
+      } else {
+        closeDependants();
+        m_tabs->removeTab(modelTypeToInt(it->first));
+        it = m_extensions.erase(it);
+      }
+      break;
+    default:
+      throw std::runtime_error("Unknown MantidMatrix extension.");
+    }
   }
 }
diff --git a/MantidPlot/src/Mantid/MantidMatrixDxExtensionHandler.cpp b/MantidPlot/src/Mantid/MantidMatrixDxExtensionHandler.cpp
index b261b76f9566ce4f0a431897ff89a4394f41f23e..99aa9c101785054c4004fd69dbf5a9268c8e2185 100644
--- a/MantidPlot/src/Mantid/MantidMatrixDxExtensionHandler.cpp
+++ b/MantidPlot/src/Mantid/MantidMatrixDxExtensionHandler.cpp
@@ -76,7 +76,7 @@ int MantidMatrixDxExtensionHandler::getPrecision(
 void MantidMatrixDxExtensionHandler::setColumnWidth(
     MantidMatrixTabExtension &extension, int width, int numberOfColumns) {
   if (extension.type == m_type) {
-    auto table_view = extension.tableView;
+    auto &table_view = extension.tableView;
     table_view->horizontalHeader()->setDefaultSectionSize(width);
     for (int i = 0; i < numberOfColumns; i++) {
       table_view->setColumnWidth(i, width);
@@ -94,7 +94,7 @@ void MantidMatrixDxExtensionHandler::setColumnWidth(
 int MantidMatrixDxExtensionHandler::getColumnWidth(
     MantidMatrixTabExtension &extension) {
   if (extension.type == m_type) {
-    auto table_view = extension.tableView;
+    auto &table_view = extension.tableView;
     return table_view->columnWidth(0);
   } else {
     return m_successor->getColumnWidth(extension);
@@ -109,7 +109,7 @@ int MantidMatrixDxExtensionHandler::getColumnWidth(
 QTableView *MantidMatrixDxExtensionHandler::getTableView(
     MantidMatrixTabExtension &extension) {
   if (extension.type == m_type) {
-    return extension.tableView;
+    return extension.tableView.get();
   } else {
     return m_successor->getTableView(extension);
   }
diff --git a/MantidPlot/src/Mantid/MantidMatrixExtensionRequest.cpp b/MantidPlot/src/Mantid/MantidMatrixExtensionRequest.cpp
index 799d1abb246407e88ad85daed53e0e604193bbb7..01b297c9b7376e57a6c60b8eff9d4080013cc5b8 100644
--- a/MantidPlot/src/Mantid/MantidMatrixExtensionRequest.cpp
+++ b/MantidPlot/src/Mantid/MantidMatrixExtensionRequest.cpp
@@ -215,7 +215,7 @@ bool MantidMatrixExtensionRequest::tableViewMatchesObject(
     MantidMatrixTabExtensionMap &extensions, QObject *object) {
   for (auto it = extensions.begin(); it != extensions.end(); ++it) {
     auto &extension = it->second;
-    if (extension.tableView == object) {
+    if (extension.tableView.get() == object) {
       return true;
     }
   }
@@ -234,7 +234,7 @@ QTableView *MantidMatrixExtensionRequest::getActiveView(
     QTableView *defaultValue) {
   if (extensions.count(type) > 0) {
     auto &extension = extensions[type];
-    return extension.tableView;
+    return extension.tableView.get();
   } else {
     return defaultValue;
   }
diff --git a/MantidPlot/src/Mantid/MantidMatrixTabExtension.h b/MantidPlot/src/Mantid/MantidMatrixTabExtension.h
index 11551f9721273d23128de3879693c431b76d89b2..e89261833c55c456af6b748efada2ffca12f5377 100644
--- a/MantidPlot/src/Mantid/MantidMatrixTabExtension.h
+++ b/MantidPlot/src/Mantid/MantidMatrixTabExtension.h
@@ -15,10 +15,10 @@ struct MantidMatrixTabExtension {
                            MantidMatrixModel::Type type)
       : label(label), tableView(tableView), model(model), type(type) {}
   MantidMatrixTabExtension()
-      : label(""), tableView(nullptr), model(nullptr),
+      : label(""), tableView(), model(nullptr),
         type(MantidMatrixModel::Type::DX) {}
   QString label;
-  QTableView *tableView;
+  std::unique_ptr<QTableView> tableView;
   QPointer<MantidMatrixModel> model;
   MantidMatrixModel::Type type;
 };
diff --git a/docs/source/release/v3.12.0/ui.rst b/docs/source/release/v3.12.0/ui.rst
index 48c549acd4c372a30ad8b4b49e787a2d97935b76..38d6848cedc4969771a238bb1195e71ed9e26269 100644
--- a/docs/source/release/v3.12.0/ui.rst
+++ b/docs/source/release/v3.12.0/ui.rst
@@ -15,7 +15,10 @@ Installation
 Workbench
 ---------
 
+- Fixed a bug where replacing a workspace with X errors with a workspace without the errors while Data View was open would result in a crash.
+
+
 SliceViewer and Vates Simple Interface
 --------------------------------------
 
-:ref:`Release 3.12.0 <v3.12.0>`
\ No newline at end of file
+:ref:`Release 3.12.0 <v3.12.0>`