Licence key registers as not valid. Please help.

Hi migueld64954392,

Please let me know the exact error message?

If its an upgrade, then it will be a two step validation, first you will have to enter the serial key of Acrobat DC followed by the previous Acrobat version selection i.e Acrobat XI & then entering the serial key for the same.

If Acrobat was purchased from Adobe, then you can find the serial key using this link  Find your serial number quickly, just to verify that the serial key you are entering is correct.

Regards,

Aadesh