offline activation

Hello,

I'm Installing Acrobat 2017 on a computer that will never have an internet connection. I tried the offline activation process by generating an offline request code. Every time that I entered the code and serial number I got a error that said the code or serial number is invalid. They are not invalid, I copy and pasted the code and I know the serial is correct. I called Adobe support and they informed me that offline activation is no longer available for my product. They suggested that I post here for further support and possibly a solution. Can anybody confirm that offline activation is no longer available? Or, help with a possible solution??? I have several computers that are offline and will need Acrobat.

Thanks in advance,

Mike