Jeez

You are right. I tried the latest firmware from your site. It was installed and activated successfully. Thanks for help!

I used Firmware from when I downloaded it last time. I didn't download new one because thought your firmware doesn't need to update.

Nope, I bought new activation code.

I have WF-3720. I don't have any errors. I can't activate it.

After last windows update my printer was also updated. And now I cannot instal chipless firmware on it. Please help!