Index: src/libchcore/TWin32ErrorFormatter.cpp
===================================================================
diff -u -N -ra6fac511b0dd40e1c18cab086e0bc5ff5d2bc8d7 -r86c2327549cd4fa98972cf9035f9a78451a00f88
--- src/libchcore/TWin32ErrorFormatter.cpp	(.../TWin32ErrorFormatter.cpp)	(revision a6fac511b0dd40e1c18cab086e0bc5ff5d2bc8d7)
+++ src/libchcore/TWin32ErrorFormatter.cpp	(.../TWin32ErrorFormatter.cpp)	(revision 86c2327549cd4fa98972cf9035f9a78451a00f88)
@@ -43,17 +43,18 @@
 		TString strData;
 		wchar_t* pszBuffer = strData.GetBuffer(dwMaxError);
 
-		DWORD dwFlags = FORMAT_MESSAGE_FROM_SYSTEM;
-		if (hModule)
-			dwFlags |= FORMAT_MESSAGE_FROM_HMODULE;
+		DWORD dwPos = 0;
+		if(hModule)
+			dwPos = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_FROM_HMODULE, hModule, dwErrorCode, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), pszBuffer, dwMaxError - 1, NULL);
+		else
+			dwPos = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, nullptr, dwErrorCode, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), pszBuffer, dwMaxError - 1, NULL);
 
-		DWORD dwPos = FormatMessage(dwFlags, hModule, dwErrorCode, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), pszBuffer, dwMaxError - 1, NULL);
 		if (dwPos == 0xffffffff)
 		{
 			int iPos = 0;
 			if (bUseNumberFallback)
 				iPos = _sntprintf_s(pszBuffer, dwMaxError, _TRUNCATE, _T("ErrorCode: 0x%lx"), dwErrorCode);
-			strData.ReleaseBufferSetLength(iPos);
+			strData.ReleaseBufferSetLength(iPos < 0 ? 0 : iPos);
 		}
 		else
 			strData.ReleaseBufferSetLength(std::min(dwPos, dwMaxError - 1));