Adobe Acrobat 8 Professional says there is no more temporary use period, that I must reactivate to use. My use was not temporary I own product since it came out. How do I reactivate?

uninstall acrobat 8 (using the uninstaller)

if win, clean per Download Adobe Reader and Acrobat Cleaner Tool - Adobe Labs

remove the cache.db file from Program Files (x86)/Common Files/Adobe/Adobe PCD/cache/

restart your computer

follow the steps here to install acrobat 8, https://helpx.adobe.com/creative-suite/kb/activation-fails-cs3-acrobat-8.html

if that fails read this, https://forums.adobe.com/thread/2385900