kglad Community Expert , Mar 15, 2017. assuming you're using a valid adobe serial number (6 groups of 4 numbers), you have a mismatch between your installation file and serial number. ie, you can have a valid serial number, but if it's for program A and your installation file is for program B, you will see an invalid serial number
3 Download the installation file from the My Adobe website to the new computer. If you purchased Acrobat from Adobe, hover your mouse over your name and select "My Orders." Click the "Download AdobeSupport Policies: Supported Product Versions. Product support is available for the products and versions listed below. Products without a version number are continuously updated, and the latest update is supported. The level of support may differ among versions and among products. Please consult the following pages for more details: eKOT.