Index: /trunk/src/VBox/Frontends/VirtualBox/src/globals/UIMessageCenter.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/globals/UIMessageCenter.cpp	(revision 78395)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/globals/UIMessageCenter.cpp	(revision 78396)
@@ -1465,4 +1465,25 @@
 }
 
+void UIMessageCenter::cannotOpenKnownMedium(const CVirtualBox &comVBox, const QUuid &uMediumId, QWidget *pParent /* = 0 */) const
+{
+    /* Show the error: */
+    error(pParent, MessageType_Error,
+          tr("Failed to open the medium with following ID: <nobr><b>%1</b></nobr>.").arg(uMediumId.toString()), UIErrorString::formatErrorInfo(comVBox));
+}
+
+void UIMessageCenter::cannotAcquireAttachmentMedium(const CMediumAttachment &comAttachment, QWidget *pParent /* = 0 */) const
+{
+    /* Show the error: */
+    error(pParent, MessageType_Error,
+          tr("Failed to acquire attachment medium."), UIErrorString::formatErrorInfo(comAttachment));
+}
+
+void UIMessageCenter::cannotAcquireMediumAttribute(const CMedium &comMedium, QWidget *pParent /* = 0 */) const
+{
+    /* Show the error: */
+    error(pParent, MessageType_Error,
+          tr("Failed to acquire medium attribute."), UIErrorString::formatErrorInfo(comMedium));
+}
+
 void UIMessageCenter::cannotCloseMedium(const UIMedium &medium, const COMResult &rc, QWidget *pParent /* = 0*/) const
 {
Index: /trunk/src/VBox/Frontends/VirtualBox/src/globals/UIMessageCenter.h
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/globals/UIMessageCenter.h	(revision 78395)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/globals/UIMessageCenter.h	(revision 78396)
@@ -343,4 +343,7 @@
     bool cannotRemountMedium(const CMachine &machine, const UIMedium &medium, bool fMount, bool fRetry, QWidget *pParent = 0) const;
     void cannotOpenMedium(const CVirtualBox &comVBox, const QString &strLocation, QWidget *pParent = 0) const;
+    void cannotOpenKnownMedium(const CVirtualBox &comVBox, const QUuid &uMediumId, QWidget *pParent = 0) const;
+    void cannotAcquireAttachmentMedium(const CMediumAttachment &comAttachment, QWidget *pParent = 0) const;
+    void cannotAcquireMediumAttribute(const CMedium &comMedium, QWidget *pParent = 0) const;
     void cannotCloseMedium(const UIMedium &medium, const COMResult &rc, QWidget *pParent = 0) const;