The free pdf unlock tool tries to crack the password of your file for two minutes.
This restriction is set in place to allow other users to share our server resources for the free version.
The password of the PDF file is too long for the free version.
You can still crack it by purchasing a dedicated server time.
By hiring the dedicated server, you will have a significantly higer chance of cracking your password.
$290 Max Time 1 month (720 million words)
$140 Max Time 1 week (200 million words)
$75 Max Recovery Time 1 day (30 million words of top most used passwords)
$28 Max Recovery Time 2 hours (2 million words of top most used passwords)
$18 Max Recovery Time 1 hour (1 million words of top most used passwords)