Your PDF document(named ebookinstall.pdf) has encrypted data, so prior to opening it you should know its password. If secret code is very complex it will be hopeless obtaining any data.
GL_n 发表于 2019-5-31 01:33
Your PDF document(named ebookinstall.pdf) has encrypted data, so prior to opening it you should know ...
Thanks for reminding. I find these words on this attached CD: 64PT-9VW4-F4SK-59KT SERIAL NUMBER IS REQUIED TO USE YOUR EBOOK. A password? How to use it? Thank you for your help in advance!!!