Hi Antonio,
I think it may be a server glitch. I will however resend you the CJT Dev license key information.
Keep in mind that CJT Pro and CJT Dev is currently at version 7.1 and not 7.1.1, which is the free version. You will know you have the free version installed if you have 7.1.1 and CSS & JavaScript Toolbox Free showing in the title. Also the free version now has a dashboard widget.
Now all of that said, and after reading your post, it seems you do have CJT Dev installed because Free does not have the license checker form.
Can you try resetting/clearing your license key and try again.
Let me know how it all goes.
Kind Regards,
Damian