I recently ran into an issue where a WSH script was calling an external executable and returning an exit code of 0 even though there had been an error running the external executable. The problem is that I was relying on oExec.StdOut.ReadAll() to block the script until the command had finished processing. The ReadAll() method functions synchronously, so if the executable had been writing to StdOut, I would have been right. Unfortunately, I was neglecting the StdErr stream. So, not only did I miss the errors that the executable threw, the script didn’t block on the executable’s output, so I returned the exit code before the executable had actually finished running. The lesson here is to always think about StdErr no matter what you’re trying to accomplish.