Same problem. I can not even find the original license code on my dashboard 
This is also happening with our site. Theme.co account shows the license is active for our site, but when logged into our site we’re getting error messages saying our license isn’t validated. Tried copy/pasting the license and it says it’s not a valid license.
SAme thing here not sure what is going on…
yep same here!
Me too, I guess they will be working on this soon!
Adding my name to the list of affected. My x theme license says it is accepted when I paste into my wordpress dashboard but upon refresh it does not take.
Hi @suzannereid (and everyone else),
Thank you for writing in to let us know about this issue. Regretfully for a short period during this transition the validation API was offline entirely. If your site tried to check for updates during that window (about an hour) it would have caused the site to become invalidated. I’m sorry about the inconvenience this has caused. You can at this time try to validate again.
Additionally, we’re still seeing an issue where some site URLs are not being considered a match even though there were in the old system. We’ll keep you up to date as we work to get this resolved.
Thanks!
Update: We have corrected an addition issue with site validation. Regretfully the new validation URL checker was too strict and was missing a large number of URLs that should have been considered a match. At this time I would recommend trying to validate your site again.
Hey there. Still not working on my end after repeated attempts.
I now get a message telling me that…
“Your code is valid but looks like it has already been used on another site. You can revoke and re-assign within your Themeco account.”
Then it becomes invalid again
Hi @mbrent and @daveoxton would you mind giving it one more try? I’ve added some additional logging to help spot discrepancies on differences in the URLs being matched. I’ll keep an eye out for the domains associated with your accounts. Thanks!
Hi @alexander ! Im also having issues, the site and the license are new. (terraandesplus.com) When entering the license code it says its ok, but when it reloads the page it shows deactivated again. 
Thanks of the help!
I just tried to add it on a staging site and i’m wondering if i’m doing something wrong. it says it’s validated, yet it loads and it’s not validated anymore. (just as @sebagc said)
The prod site is: https://makewebbetter.com/
and the staging site where i’m trying to test it is: https://demo.makewebbetter.com/userenv/demomwb_D8f7ljO4mV6O
I literally tried less than a minute ago, so the problem seems to still be there.
Still says it looks like it has already been used on another site. I do have another licence on another site and it is doing the same on that site too.
Same issue. Won’t validate.
Same here, tried multiple licenses. Same thing, says validated then jumps straight to not validated.
same here… seems to be a bigger problem…
Getting somewhere. Narrowed it down to Pro licenses. We’ll circle back as soon as we know more.
Found what we think is the issue. Working on a fix now and will post back when it’s ready to test.