file can not open by adobe professional 8

[ektrontek]

Hi, 

I face one condition, one file can not open by adobe professional 8, but it can by adobe reader dc or adobe profession2017 or more new version. When I open it by adobe professional 8 , it show message as listed as below

There was an error opening this file, acrobat could not decrypt this file

Because product security issue, I can not remove security setting from the file, is there suggestion which I can open it by adobe professional 8? Thanks a lot.

Regards, Hsu Yao Chang

[try67]

If the file was secured using a 256-bit AES policy then it can't be opened using versions earlier than Acrobat/Reader X.

You really should not be using such an ancient version as Acrobat 8. It's a serious security risk.

[ektrontek]

Is there official article or information about it's detail? Thanks a lot.