I lost my paid mode.

How can I make you pay attention to this issue? ^^

You can close this.
I figured out, that the old activation link still works.

I had almost the same situation for few months (no time to search for a fix), except I lost Paid mode status / License / Activation by logging onto another computer with my google account and activating Tabs Outliner synchronization (at work). Same day after getting back from work I noticed TO asks about authorization to backup my tree with Google Drive on my home computer. I did what it asked, but each time I would start Chrome at home, it would ask for it again, again... and again.

Just today I read your support ticket and it worked like a charm, clicked activation link in purchase confirmation e-mail and BAM, TO works again :)

Thousand Thanks for writing followup comment with answer for the problem :)

It seems that I have to click on an activation link in the purchase confirmation email... But what if I don't have this purchase confirmation email any more?