Reinstalled Acrobat XI Pro after reformatting my HD from Win 7 Pro 32 bit to 64 bit.
The reinstall worked for a few weeks, then messages keep popping up to upgrade to DC. Don't want to upgrade to DC. Went to use today, pop up asks me to log into my Adobe ID. I log in. Asks me to enter product serial number. I do and message says Product Key is invalid.
What am I doing wrong?