Index: /trunk/src/VBox/Runtime/generic/http-curl.cpp
===================================================================
--- /trunk/src/VBox/Runtime/generic/http-curl.cpp	(revision 68967)
+++ /trunk/src/VBox/Runtime/generic/http-curl.cpp	(revision 68968)
@@ -1713,8 +1713,11 @@
                     {
                         DWORD dwErr = GetLastError();
-                        if (dwErr == ERROR_WINHTTP_AUTODETECTION_FAILED)
+                        if (   dwErr == ERROR_WINHTTP_AUTODETECTION_FAILED
+                            || (   dwErr == ERROR_WINHTTP_UNRECOGNIZED_SCHEME
+                                && (   RTStrNICmp(pszUrl, RT_STR_TUPLE("https://")) == 0
+                                    || RTStrNICmp(pszUrl, RT_STR_TUPLE("http://")) == 0) ) )
                             rcRet = rtHttpUpdateAutomaticProxyDisable(pThis);
                         else
-                            AssertMsgFailed(("g_pfnWinHttpGetProxyForUrl -> %u\n", dwErr));
+                            AssertMsgFailed(("g_pfnWinHttpGetProxyForUrl(%s) -> %u\n", pszUrl, dwErr));
                     }
                     RTUtf16Free(pwszUrl);