Encrypt with password- Help

I created a pdf, used Advanced/Security/Encrypt with Password.  I did not provide a password..  Acrobat must have.  How do I find or fix?What did acrobat use to create the password?  I was expecting a prompt.  Next thing I know its protected with an unknown pw?  Help.

Thanks

It is looking for a 'permissions password'.  I did not provide one.  My bad here it seems.