Cannot enter the 16 digit access code to add computer to existing account

Trying to add a new computer to an existing Webroot account but can only type letters into the boxes - numbers don't enter.  I switched to a hard wired keyboard and same thing.  I then typed the 16 digit code into Word and copied and pasted into the first box and got 12 continuous letters pasted without any numbers.  I did the same with a different 16 digit code that came with the new computer.  What am I doing wrong?