I have a license key for Premiere Elements 13. Right after I opened PrE just now, my mac book pro crashed. After mac book pro rebooted, PrE asked me for license key. But after entering the key again, I still got the trial version watermark on my project. I contacted customer support via chat after login Adobe ID. Chatted with the first customer support guy for 10 mins (most of the time was his asking me to wait) and he did not seem to have a clue, then transferred me to a "technical support" guy. Then chatted with this guy for 14 mins (and of course "wait" most of the time). Came back and ask me to go to forums.adobe.com to get this resolved. Then I asked him if he could just reset the number of computer previously registered with the license key on the system. He just hang up on him and end the chat session!! Uh! That is customer service via chat.
I have the case number [# removed by moderator] and the log of the chat.
This is not Adobe. Rather essentially user to user forum.
When you received the tryout dialog with the License this Product or Buy options, did you select License this Product and that route failed when using your purchased serial number?
When that happened where else did that purchase activated serial number exist --nowhere except in the computer where you were?
Did you get any messages about the purchased activated serial number being on too many of your computers?
Please reopen the computer and try again with antivirus and firewalls disabled. Did that make a difference or problem still there?
If all else fails, consider uninstall, free ccleaner run through, and reinstall with antivirus and firewalls disabled if applicable to Mac.
Add On ...since this is not Adobe and is a public forum, please do not put any personal information and numbers in the post to protect your privacy.