Index: /trunk/src/VBox/Main/src-client/GuestSessionImpl.cpp
===================================================================
--- /trunk/src/VBox/Main/src-client/GuestSessionImpl.cpp	(revision 50770)
+++ /trunk/src/VBox/Main/src-client/GuestSessionImpl.cpp	(revision 50771)
@@ -3080,7 +3080,7 @@
     LogFlowThisFuncEnter();
 
-    Bstr strSharingMode = ""; /* Sharing mode is ignored. */
-
-    return fileOpenEx(aPath, aOpenMode, aDisposition, strSharingMode.raw(), aCreationMode,
+    Utf8Str strSharingMode = ""; /* Sharing mode is ignored. */
+
+    return fileOpenEx(aPath, aOpenMode, aDisposition, strSharingMode, aCreationMode,
                       0 /* aOffset */, aFile);
 #endif /* VBOX_WITH_GUEST_CONTROL */