diff --git a/AUTHORS.md b/AUTHORS.md
index 44c8fbc2e8..0939409926 100644
--- a/AUTHORS.md
+++ b/AUTHORS.md
@@ -76,6 +76,7 @@ Programmers
     Eduard Cot (trombonecot)
     Eli2
     Emanuel Guével (potatoesmaster)
+    Eris Caffee (eris)
     eroen
     escondida
     Evgeniy Mineev (sandstranger)
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 30f02bed33..2141d20007 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -114,6 +114,7 @@
     Feature #1465: "Reset" argument for AI functions
     Feature #2491: Ability to make OpenMW "portable"
     Feature #2554: Modifying an object triggers the instances table to scroll to the corresponding record
+    Feature #2766: Warn user if their version of Morrowind is not the latest.
     Feature #2780: A way to see current OpenMW version in the console
     Feature #3245: Grid and angle snapping for the OpenMW-CS
     Feature #3616: Allow Zoom levels on the World Map
diff --git a/apps/launcher/maindialog.cpp b/apps/launcher/maindialog.cpp
index 167f6b9c26..accb27a48b 100644
--- a/apps/launcher/maindialog.cpp
+++ b/apps/launcher/maindialog.cpp
@@ -570,7 +570,7 @@ void Launcher::MainDialog::play()
         msgBox.setStandardButtons(QMessageBox::Ok);
         msgBox.setText(tr("<br><b>You do not have a game file selected.</b><br><br> \
                           OpenMW will not start without a game file selected.<br>"));
-                          msgBox.exec();
+        msgBox.exec();
         return;
     }
 
diff --git a/apps/wizard/existinginstallationpage.cpp b/apps/wizard/existinginstallationpage.cpp
index 886fcd95db..42b7766693 100644
--- a/apps/wizard/existinginstallationpage.cpp
+++ b/apps/wizard/existinginstallationpage.cpp
@@ -123,6 +123,11 @@ void Wizard::ExistingInstallationPage::on_browseButton_clicked()
         return;
     }
 
+    if (!versionIsOK(info.absolutePath()))
+    {
+        return;
+    }
+
     QString path(QDir::toNativeSeparators(info.absolutePath()));
     QList<QListWidgetItem*> items = installationsList->findItems(path, Qt::MatchExactly);
 
@@ -165,3 +170,36 @@ int Wizard::ExistingInstallationPage::nextId() const
 {
     return MainWizard::Page_LanguageSelection;
 }
+
+bool Wizard::ExistingInstallationPage::versionIsOK(QString directory_name)
+{
+    QDir directory = QDir(directory_name);
+    QFileInfoList infoList = directory.entryInfoList(QStringList(QString("Morrowind.bsa")));
+    if (infoList.size() == 1)
+    {
+        qint64 actualFileSize = infoList.at(0).size();
+        const qint64 expectedFileSize = 310459500; // Size of Morrowind.bsa in Steam and GOG editions.
+
+        if (actualFileSize == expectedFileSize)
+        {
+            return true;
+        }
+
+        QMessageBox msgBox;
+        msgBox.setWindowTitle(QObject::tr("Most recent Morrowind not detected"));
+        msgBox.setIcon(QMessageBox::Warning);
+        msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
+        msgBox.setDefaultButton(QMessageBox::No);
+        msgBox.setText(QObject::tr("<br><b>There may be a more recent version of Morrowind available.</b><br><br>\
+                              Do you wish to continue anyway?<br>"));
+        int ret = msgBox.exec();
+        if (ret == QMessageBox::Yes)
+        {
+            return true;
+        }
+
+        return false;
+    }
+
+    return false;
+}
diff --git a/apps/wizard/existinginstallationpage.hpp b/apps/wizard/existinginstallationpage.hpp
index fbbbe432ee..6bdc5df134 100644
--- a/apps/wizard/existinginstallationpage.hpp
+++ b/apps/wizard/existinginstallationpage.hpp
@@ -3,6 +3,8 @@
 
 #include "ui_existinginstallationpage.h"
 
+#include <components/config/gamesettings.hpp>
+
 namespace Wizard
 {
     class MainWizard;
@@ -25,9 +27,10 @@ namespace Wizard
     private:
         MainWizard *mWizard;
 
+        bool versionIsOK(QString directory_name);
+
     protected:
         void initializePage() override;
-
     };
 
 }
diff --git a/apps/wizard/installationpage.cpp b/apps/wizard/installationpage.cpp
index 9c90b0bbf7..8aad714be3 100644
--- a/apps/wizard/installationpage.cpp
+++ b/apps/wizard/installationpage.cpp
@@ -8,8 +8,9 @@
 
 #include "mainwizard.hpp"
 
-Wizard::InstallationPage::InstallationPage(QWidget *parent) :
-    QWizardPage(parent)
+Wizard::InstallationPage::InstallationPage(QWidget *parent, Config::GameSettings &gameSettings) :
+    QWizardPage(parent),
+    mGameSettings(gameSettings)
 {
     mWizard = qobject_cast<MainWizard*>(parent);
 
@@ -18,7 +19,7 @@ Wizard::InstallationPage::InstallationPage(QWidget *parent) :
     mFinished = false;
 
     mThread = new QThread();
-    mUnshield = new UnshieldWorker();
+    mUnshield = new UnshieldWorker(mGameSettings.value("morrowind-bsa-filesize").toLongLong());
     mUnshield->moveToThread(mThread);
 
     connect(mThread, SIGNAL(started()),
@@ -47,6 +48,10 @@ Wizard::InstallationPage::InstallationPage(QWidget *parent) :
 
     connect(mUnshield, SIGNAL(requestFileDialog(Wizard::Component)),
             this, SLOT(showFileDialog(Wizard::Component)), Qt::QueuedConnection);
+
+    connect(mUnshield, SIGNAL(requestOldVersionDialog()),
+            this, SLOT(showOldVersionDialog())
+            , Qt::QueuedConnection);
 }
 
 Wizard::InstallationPage::~InstallationPage()
@@ -181,6 +186,34 @@ void Wizard::InstallationPage::showFileDialog(Wizard::Component component)
     mUnshield->setDiskPath(path);
 }
 
+void Wizard::InstallationPage::showOldVersionDialog()
+{
+    logTextEdit->appendHtml(tr("<p>Detected old version of component Morrowind.</p>"));
+    mWizard->addLogText(tr("Detected old version of component Morrowind."));
+
+    QMessageBox msgBox;
+    msgBox.setWindowTitle(tr("Morrowind Installation"));
+    msgBox.setIcon(QMessageBox::Information);
+    msgBox.setText(QObject::tr("There may be a more recent version of Morrowind available.<br><br>Do you wish to continue anyway?"));
+    msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
+    msgBox.setDefaultButton(QMessageBox::No);
+
+    int ret = msgBox.exec();
+    if (ret == QMessageBox::No)
+    {
+        logTextEdit->appendHtml(tr("<p><br/><span style=\"color:red;\"> \
+                                    <b>Error: The installation was aborted by the user</b></span></p>"));
+
+        mWizard->addLogText(QLatin1String("Error: The installation was aborted by the user"));
+        mWizard->mError = true;
+
+        emit completeChanged();
+        return;
+    }
+
+    mUnshield->wakeAll();
+}
+
 void Wizard::InstallationPage::installationFinished()
 {
     QMessageBox msgBox;
diff --git a/apps/wizard/installationpage.hpp b/apps/wizard/installationpage.hpp
index 97b1fa8bf7..49c92a5f31 100644
--- a/apps/wizard/installationpage.hpp
+++ b/apps/wizard/installationpage.hpp
@@ -6,6 +6,7 @@
 #include "unshield/unshieldworker.hpp"
 #include "ui_installationpage.h"
 #include "inisettings.hpp"
+#include <components/config/gamesettings.hpp>
 
 class QThread;
 
@@ -19,7 +20,7 @@ namespace Wizard
     {
         Q_OBJECT
     public:
-        InstallationPage(QWidget *parent);
+        InstallationPage(QWidget *parent, Config::GameSettings &gameSettings);
         ~InstallationPage() override;
 
         int nextId() const override;
@@ -34,8 +35,11 @@ namespace Wizard
 
         void startInstallation();
 
+        Config::GameSettings &mGameSettings;
+
     private slots:
         void showFileDialog(Wizard::Component component);
+        void showOldVersionDialog();
 
         void installationFinished();
         void installationError(const QString &text, const QString &details);
diff --git a/apps/wizard/mainwizard.cpp b/apps/wizard/mainwizard.cpp
index 7987d9b08d..268aaf15af 100644
--- a/apps/wizard/mainwizard.cpp
+++ b/apps/wizard/mainwizard.cpp
@@ -325,7 +325,7 @@ void Wizard::MainWizard::setupPages()
     setPage(Page_InstallationTarget, new InstallationTargetPage(this, mCfgMgr));
     setPage(Page_ComponentSelection, new ComponentSelectionPage(this));
 #ifdef OPENMW_USE_UNSHIELD
-    setPage(Page_Installation, new InstallationPage(this));
+    setPage(Page_Installation, new InstallationPage(this, mGameSettings));
 #endif
     setPage(Page_Import, new ImportPage(this));
     setPage(Page_Conclusion, new ConclusionPage(this));
diff --git a/apps/wizard/unshield/unshieldworker.cpp b/apps/wizard/unshield/unshieldworker.cpp
index 14a34e8779..3b68f87cc1 100644
--- a/apps/wizard/unshield/unshieldworker.cpp
+++ b/apps/wizard/unshield/unshieldworker.cpp
@@ -12,8 +12,9 @@
 #include <QDir>
 #include <QDirIterator>
 
-Wizard::UnshieldWorker::UnshieldWorker(QObject *parent) :
+Wizard::UnshieldWorker::UnshieldWorker(qint64 expectedMorrowindBsaSize, QObject *parent) :
     QObject(parent),
+    mExpectedMorrowindBsaSize(expectedMorrowindBsaSize),
     mIniSettings()
 {
     unshield_set_log_level(0);
@@ -159,6 +160,11 @@ void Wizard::UnshieldWorker::setIniCodec(QTextCodec *codec)
     mIniCodec = codec;
 }
 
+void Wizard::UnshieldWorker::wakeAll()
+{
+    mWait.wakeAll();
+}
+
 bool Wizard::UnshieldWorker::setupSettings()
 {
     // Create Morrowind.ini settings map
@@ -478,6 +484,18 @@ bool Wizard::UnshieldWorker::setupComponent(Component component)
                     // Check if we have correct archive, other archives have Morrowind.bsa too
                     if (tribunalFound == bloodmoonFound)
                     {
+                        qint64 actualFileSize = getMorrowindBsaFileSize(file);
+                        if (actualFileSize != mExpectedMorrowindBsaSize)
+                        {
+                            QReadLocker readLock(&mLock);
+                            emit requestOldVersionDialog();
+                            mWait.wait(&mLock);
+                            if (mStopped)
+                            {
+                                qDebug() << "We are asked to stop !!";
+                                break;
+                            }
+                        }
                         cabFile = file;
                         found = true; // We have a GoTY disk or a Morrowind-only disk
                     }
@@ -492,6 +510,11 @@ bool Wizard::UnshieldWorker::setupComponent(Component component)
 
         }
 
+        if (cabFile.isEmpty())
+        {
+            break;
+        }
+
         if (!found)
         {
             emit textChanged(tr("Failed to find a valid archive containing %1.bsa! Retrying.").arg(name));
@@ -939,3 +962,42 @@ bool Wizard::UnshieldWorker::findInCab(const QString &fileName, const QString &c
     unshield_close(unshield);
     return false;
 }
+
+size_t Wizard::UnshieldWorker::getMorrowindBsaFileSize(const QString &cabFile)
+{
+    QString fileName = QString("Morrowind.bsa");
+    QByteArray array(cabFile.toUtf8());
+
+    Unshield *unshield;
+    unshield = unshield_open(array.constData());
+
+    if (!unshield)
+    {
+        emit error(tr("Failed to open InstallShield Cabinet File."), tr("Opening %1 failed.").arg(cabFile));
+        unshield_close(unshield);
+        return false;
+    }
+
+    for (int i = 0; i < unshield_file_group_count(unshield); ++i)
+    {
+        UnshieldFileGroup *group = unshield_file_group_get(unshield, i);
+
+        for (size_t j = group->first_file; j <= group->last_file; ++j)
+        {
+
+            if (unshield_file_is_valid(unshield, j))
+            {
+                QString current(QString::fromUtf8(unshield_file_name(unshield, j)));
+                if (current.toLower() == fileName.toLower())
+                {
+                    size_t fileSize = unshield_file_size(unshield, j);
+                    unshield_close(unshield);
+                    return fileSize; // File is found!
+                }
+            }
+        }
+    }
+
+    unshield_close(unshield);
+    return 0;
+}
diff --git a/apps/wizard/unshield/unshieldworker.hpp b/apps/wizard/unshield/unshieldworker.hpp
index 13f4a1168c..483264e990 100644
--- a/apps/wizard/unshield/unshieldworker.hpp
+++ b/apps/wizard/unshield/unshieldworker.hpp
@@ -12,6 +12,7 @@
 
 #include "../inisettings.hpp"
 
+#include <components/config/gamesettings.hpp>
 
 namespace Wizard
 {
@@ -26,7 +27,7 @@ namespace Wizard
         Q_OBJECT
 
     public:
-        UnshieldWorker(QObject *parent = nullptr);
+        UnshieldWorker(qint64 expectedMorrowindBsaSize, QObject *parent = nullptr);
         ~UnshieldWorker() override;
 
         void stopWorker();
@@ -38,6 +39,8 @@ namespace Wizard
         void setPath(const QString &path);
         void setIniPath(const QString &path);
 
+        void wakeAll();
+
         QString getPath();
         QString getIniPath();
 
@@ -45,8 +48,9 @@ namespace Wizard
 
         bool setupSettings();
 
-    private:
+        size_t getMorrowindBsaFileSize(const QString &cabFile);
 
+    private:
         bool writeSettings();
 
         bool getInstallComponent(Component component);
@@ -95,6 +99,8 @@ namespace Wizard
 
         bool mStopped;
 
+        qint64 mExpectedMorrowindBsaSize;
+
         QString mPath;
         QString mIniPath;
         QString mDiskPath;
@@ -113,6 +119,7 @@ namespace Wizard
     signals:
         void finished();
         void requestFileDialog(Wizard::Component component);
+        void requestOldVersionDialog();
 
         void textChanged(const QString &text);