diff --git a/reactos/base/applications/mplay32/lang/bg-BG.rc b/reactos/base/applications/mplay32/lang/bg-BG.rc
index 094f82da059..71ad20bb529 100644
--- a/reactos/base/applications/mplay32/lang/bg-BG.rc
+++ b/reactos/base/applications/mplay32/lang/bg-BG.rc
@@ -38,4 +38,5 @@ BEGIN
     IDS_APPTITLE "Мултимедийният възпроизводител на РеактОС"
     IDS_PLAY "Възпроизвеждане"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/cs-CZ.rc b/reactos/base/applications/mplay32/lang/cs-CZ.rc
index 54b2642e454..05e0528bb53 100644
--- a/reactos/base/applications/mplay32/lang/cs-CZ.rc
+++ b/reactos/base/applications/mplay32/lang/cs-CZ.rc
@@ -39,4 +39,5 @@ BEGIN
     IDS_APPTITLE "ReactOS Přehrávač multimédií"
     IDS_PLAY "Přehrát"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/de-DE.rc b/reactos/base/applications/mplay32/lang/de-DE.rc
index da981305d96..10dfb85d4cc 100644
--- a/reactos/base/applications/mplay32/lang/de-DE.rc
+++ b/reactos/base/applications/mplay32/lang/de-DE.rc
@@ -34,4 +34,5 @@ BEGIN
     IDS_APPTITLE "ReactOS Multimedia Player"
     IDS_PLAY "Abspielen"
     IDS_DEFAULTMCIERRMSG "Für diesen Fehler steht keine Beschreibung zur Verfügung"
+    IDS_UNKNOWNFILEEXT "Kann keinen Gerätetyp aus der angegebenen Dateinamenerweiterung ermitteln."
 END
diff --git a/reactos/base/applications/mplay32/lang/en-US.rc b/reactos/base/applications/mplay32/lang/en-US.rc
index 1d051caff2f..ce326d352f1 100644
--- a/reactos/base/applications/mplay32/lang/en-US.rc
+++ b/reactos/base/applications/mplay32/lang/en-US.rc
@@ -34,4 +34,5 @@ BEGIN
     IDS_APPTITLE "ReactOS Multimedia Player"
     IDS_PLAY "Play"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/es-ES.rc b/reactos/base/applications/mplay32/lang/es-ES.rc
index 32820edce02..dbf0f6eb350 100644
--- a/reactos/base/applications/mplay32/lang/es-ES.rc
+++ b/reactos/base/applications/mplay32/lang/es-ES.rc
@@ -34,4 +34,5 @@ BEGIN
     IDS_APPTITLE "Reproductor Multimedia de ReactOS"
     IDS_PLAY "Reproducir"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/fr-FR.rc b/reactos/base/applications/mplay32/lang/fr-FR.rc
index 9a16e97fd2c..db3b38daa26 100644
--- a/reactos/base/applications/mplay32/lang/fr-FR.rc
+++ b/reactos/base/applications/mplay32/lang/fr-FR.rc
@@ -34,4 +34,5 @@ BEGIN
     IDS_APPTITLE "ReactOS Multimedia Player"
     IDS_PLAY "Lire"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/he-IL.rc b/reactos/base/applications/mplay32/lang/he-IL.rc
index b4509eae544..56c18d82449 100644
--- a/reactos/base/applications/mplay32/lang/he-IL.rc
+++ b/reactos/base/applications/mplay32/lang/he-IL.rc
@@ -34,4 +34,5 @@ BEGIN
     IDS_APPTITLE "נגן המולטימדיה של ReactOS"
     IDS_PLAY "נגן"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/it-IT.rc b/reactos/base/applications/mplay32/lang/it-IT.rc
index 3787b5fe3ed..c45d241caf2 100644
--- a/reactos/base/applications/mplay32/lang/it-IT.rc
+++ b/reactos/base/applications/mplay32/lang/it-IT.rc
@@ -34,4 +34,5 @@ BEGIN
     IDS_APPTITLE "Riproduttore multimediale ReactOS"
     IDS_PLAY "Riproduci"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/ja-JP.rc b/reactos/base/applications/mplay32/lang/ja-JP.rc
index cb620a0818e..f8856aad263 100644
--- a/reactos/base/applications/mplay32/lang/ja-JP.rc
+++ b/reactos/base/applications/mplay32/lang/ja-JP.rc
@@ -34,4 +34,5 @@ BEGIN
     IDS_APPTITLE "ReactOS マルチメディア プレーヤー"
     IDS_PLAY "再生"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/nl-NL.rc b/reactos/base/applications/mplay32/lang/nl-NL.rc
index 228f59d5692..bf8dc6a317f 100644
--- a/reactos/base/applications/mplay32/lang/nl-NL.rc
+++ b/reactos/base/applications/mplay32/lang/nl-NL.rc
@@ -34,4 +34,5 @@ BEGIN
     IDS_APPTITLE "ReactOS Multimedia Player"
     IDS_PLAY "Play"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/no-NO.rc b/reactos/base/applications/mplay32/lang/no-NO.rc
index 558d5127973..ccc77a535c2 100644
--- a/reactos/base/applications/mplay32/lang/no-NO.rc
+++ b/reactos/base/applications/mplay32/lang/no-NO.rc
@@ -34,4 +34,5 @@ BEGIN
     IDS_APPTITLE "ReactOS Multimedia avspiller"
     IDS_PLAY "Spill"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/pl-PL.rc b/reactos/base/applications/mplay32/lang/pl-PL.rc
index 1b89df31e3f..5c21137ef55 100644
--- a/reactos/base/applications/mplay32/lang/pl-PL.rc
+++ b/reactos/base/applications/mplay32/lang/pl-PL.rc
@@ -41,4 +41,5 @@ BEGIN
     IDS_APPTITLE "ReactOS Multimedia Player"
     IDS_PLAY "Odtwórz"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/pt-BR.rc b/reactos/base/applications/mplay32/lang/pt-BR.rc
index 5724bfb2097..e1bf6e24caf 100644
--- a/reactos/base/applications/mplay32/lang/pt-BR.rc
+++ b/reactos/base/applications/mplay32/lang/pt-BR.rc
@@ -36,4 +36,5 @@ BEGIN
     IDS_APPTITLE "ReactOS Multimedia Player"
     IDS_PLAY "Executar"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/ro-RO.rc b/reactos/base/applications/mplay32/lang/ro-RO.rc
index c95e48f008f..6490db17f23 100644
--- a/reactos/base/applications/mplay32/lang/ro-RO.rc
+++ b/reactos/base/applications/mplay32/lang/ro-RO.rc
@@ -40,4 +40,5 @@ BEGIN
     IDS_APPTITLE "Lector multimedia"
     IDS_PLAY "Lecturare"
     IDS_DEFAULTMCIERRMSG "Nu există descriere pentru această eroare"
+	IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/ru-RU.rc b/reactos/base/applications/mplay32/lang/ru-RU.rc
index 58355bd5f28..260b738898b 100644
--- a/reactos/base/applications/mplay32/lang/ru-RU.rc
+++ b/reactos/base/applications/mplay32/lang/ru-RU.rc
@@ -34,4 +34,5 @@ BEGIN
     IDS_APPTITLE "Проигрыватель ReactOS"
     IDS_PLAY "Воспроизвести"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/sk-SK.rc b/reactos/base/applications/mplay32/lang/sk-SK.rc
index 06786d6391b..9f52f4f0f71 100644
--- a/reactos/base/applications/mplay32/lang/sk-SK.rc
+++ b/reactos/base/applications/mplay32/lang/sk-SK.rc
@@ -39,4 +39,5 @@ BEGIN
     IDS_APPTITLE "Multimediálny prehrávač systému ReactOS"
     IDS_PLAY "Prehrať"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/sq-AL.rc b/reactos/base/applications/mplay32/lang/sq-AL.rc
index 60f1acefc20..20d2af13b21 100644
--- a/reactos/base/applications/mplay32/lang/sq-AL.rc
+++ b/reactos/base/applications/mplay32/lang/sq-AL.rc
@@ -38,4 +38,5 @@ BEGIN
     IDS_APPTITLE "Programi muzikor i ReactOS"
     IDS_PLAY "Fillo"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/sv-SE.rc b/reactos/base/applications/mplay32/lang/sv-SE.rc
index da17bec4694..dec23858ef3 100644
--- a/reactos/base/applications/mplay32/lang/sv-SE.rc
+++ b/reactos/base/applications/mplay32/lang/sv-SE.rc
@@ -41,4 +41,5 @@ BEGIN
     IDS_APPTITLE "ReactOS Multimediaspelare"
     IDS_PLAY "Play"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/tr-TR.rc b/reactos/base/applications/mplay32/lang/tr-TR.rc
index 187004ca956..3ea689d897b 100644
--- a/reactos/base/applications/mplay32/lang/tr-TR.rc
+++ b/reactos/base/applications/mplay32/lang/tr-TR.rc
@@ -36,4 +36,5 @@ BEGIN
     IDS_APPTITLE "Ortam Oynatıcısı"
     IDS_PLAY "Çal"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/uk-UA.rc b/reactos/base/applications/mplay32/lang/uk-UA.rc
index 395a693fc9e..724bf0f4faf 100644
--- a/reactos/base/applications/mplay32/lang/uk-UA.rc
+++ b/reactos/base/applications/mplay32/lang/uk-UA.rc
@@ -42,4 +42,5 @@ BEGIN
     IDS_APPTITLE "Програвач ReactOS"
     IDS_PLAY "Відтворити"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/zh-CN.rc b/reactos/base/applications/mplay32/lang/zh-CN.rc
index 3c3068d3574..3106fc6db1a 100644
--- a/reactos/base/applications/mplay32/lang/zh-CN.rc
+++ b/reactos/base/applications/mplay32/lang/zh-CN.rc
@@ -36,4 +36,5 @@ BEGIN
     IDS_APPTITLE "ReactOS 多媒体播放器"
     IDS_PLAY "播放"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/lang/zh-TW.rc b/reactos/base/applications/mplay32/lang/zh-TW.rc
index a2a8bdeb8c6..63689ebf776 100644
--- a/reactos/base/applications/mplay32/lang/zh-TW.rc
+++ b/reactos/base/applications/mplay32/lang/zh-TW.rc
@@ -42,4 +42,5 @@ BEGIN
     IDS_APPTITLE "ReactOS 多媒體播放器"
     IDS_PLAY "播放"
     IDS_DEFAULTMCIERRMSG "No description is available for this error"
+    IDS_UNKNOWNFILEEXT "Cannot determine the device type from the given filename extension."
 END
diff --git a/reactos/base/applications/mplay32/mplay32.c b/reactos/base/applications/mplay32/mplay32.c
index e5dc33009b6..f4220f2feb3 100644
--- a/reactos/base/applications/mplay32/mplay32.c
+++ b/reactos/base/applications/mplay32/mplay32.c
@@ -216,7 +216,7 @@ CloseMciDevice(VOID)
 
     DisableMenuItems();
 
-    return TRUE;
+    return 0;
 }
 
 static DWORD
@@ -241,7 +241,6 @@ OpenMciDevice(HWND hwnd, LPTSTR lpType, LPTSTR lpFileName)
     dwError = mciSendCommand(0, MCI_OPEN, MCI_OPEN_TYPE | MCI_OPEN_ELEMENT | MCI_WAIT, (DWORD_PTR)&mciOpen);
     if (dwError != 0)
     {
-        ShowMCIError(hwnd, dwError);
         return dwError;
     }
 
@@ -250,7 +249,6 @@ OpenMciDevice(HWND hwnd, LPTSTR lpType, LPTSTR lpFileName)
     dwError = mciSendCommand(mciOpen.wDeviceID, MCI_STATUS, MCI_STATUS_ITEM | MCI_WAIT, (DWORD_PTR)&mciStatus);
     if (dwError != 0)
     {
-        ShowMCIError(hwnd, dwError);
         return dwError;
     }
 
@@ -287,7 +285,7 @@ OpenMciDevice(HWND hwnd, LPTSTR lpType, LPTSTR lpFileName)
 
     EnableMenuItems();
 
-    return TRUE;
+    return 0;
 }
 
 static VOID
@@ -415,7 +413,7 @@ ShowDeviceProperties(HWND hwnd)
     dwError = mciSendCommand(wDeviceId, MCI_CONFIGURE, MCI_WAIT, (DWORD_PTR)&mciGeneric);
     if (dwError != 0)
     {
-        MessageBox(0, _T("Can't display the device properties!"), NULL, MB_OK);
+        ShowMCIError(hwnd, dwError);
     }
 }
 
@@ -448,7 +446,6 @@ PlayFile(HWND hwnd, LPTSTR lpFileName)
     TCHAR szLocalFileName[MAX_PATH];
     TCHAR szDeviceName[MAX_PATH];
     DWORD dwSize;
-    BOOL IsSupported;
     MCIERROR mciError;
 
     if (lpFileName == NULL)
@@ -470,11 +467,21 @@ PlayFile(HWND hwnd, LPTSTR lpFileName)
 
     dwSize = sizeof(szDeviceName) - 2;
     _tcsnset(szDeviceName, _T('\0'), dwSize / sizeof(TCHAR));
-    IsSupported = IsSupportedFileExtension(szLocalFileName, szDeviceName, &dwSize);
 
-    if (IsSupported == TRUE)
+    if (!IsSupportedFileExtension(szLocalFileName, szDeviceName, &dwSize))
     {
-        OpenMciDevice(hwnd, szDeviceName, szLocalFileName);
+        TCHAR szErrorMessage[256];
+
+        LoadString(hInstance, IDS_UNKNOWNFILEEXT, szErrorMessage, sizeof(szErrorMessage) / sizeof(TCHAR));
+        MessageBox(hwnd, szErrorMessage, szAppTitle, MB_OK | MB_ICONEXCLAMATION);
+        return;
+    }
+
+    mciError = OpenMciDevice(hwnd, szDeviceName, szLocalFileName);
+    if (mciError != 0)
+    {
+        ShowMCIError(hwnd, mciError);
+        return;
     }
 
     SetTimer(hwnd, IDT_PLAYTIMER, 100, (TIMERPROC) PlayTimerProc);
@@ -540,7 +547,7 @@ MainWndProc(HWND hwnd, UINT Message, WPARAM wParam, LPARAM lParam)
             TCHAR droppedfile[MAX_PATH];
             
             drophandle = (HDROP)wParam;
-            DragQueryFile(drophandle, 0, droppedfile, sizeof(droppedfile));
+            DragQueryFile(drophandle, 0, droppedfile, sizeof(droppedfile) / sizeof(TCHAR));
             DragFinish(drophandle);
             PlayFile(hwnd, droppedfile);
             break;
diff --git a/reactos/base/applications/mplay32/resource.h b/reactos/base/applications/mplay32/resource.h
index ea7588585e0..19c6d3eac3f 100644
--- a/reactos/base/applications/mplay32/resource.h
+++ b/reactos/base/applications/mplay32/resource.h
@@ -25,6 +25,7 @@
 #define IDS_ALL_TYPES_FILTER 108
 #define IDS_PLAY             109
 #define IDS_DEFAULTMCIERRMSG 110
+#define IDS_UNKNOWNFILEEXT   111
 
 /* Menu */
 #define IDR_MAINMENU 500