Advertisements Well then that's not the issue. Only two other potential issues I can think of... 1) There is a slight issue with the naming that could cause it to try to overwrite an existing file during the decryption phase. tivolibre doesn't allow that so if the output file name passed in already exists then it simply fails. Could that be an issue here? 2) Could your antivirus software be blocking this somehow? I'm using the built in Windows 10 AV on my machine. Are you using something else? If so try adding an exception to it for the whole pyTivo install directory and see if that helps. Other then that I'm stumped. I've tried it on every machine I have and it always works, so I'm not sure why it's not for you. Even more perplexing is why that one time it did. If it were a constant failure that would be one thing, but intermittent failure is even harder to diagnose.