Getting the error message "The serial number you entered is not valid" when entering a serial number
I had CS4 running on my old G5 since 2009. I've recently bought an iMac and couldn't install CS4 off the original disk, so I downloaded it again from the adobe website. When asked for my serial number I entered it but got an error message "The serial number you entered is not valid" It is the original serial number though and should work. I only ever had CS4 on that G5 and no other machine. OS is Yosemite. Why is it giving me this error?