We are having this issue with our websites. I can see an update for Toolset Views on multiple websites. All I have tried to update have said I need to register the site to receive updates.
Initially when I tried to log in to my account I was being redirected to wpml.org. I had to manually type in https://toolset.com/account to see a maintenance message.
Once the maintenance message cleared and I was able to login I attempted to reregister the sites with their existing key and received the "Invalid site key for the current site" error. I have also deleted and resubmit the site with the same error. This is both with http:// and https:// (sites are hidden link) as well as explicitly copying the URL supplied to me on the registration page in WordPress.
We have the same problem, when I enter the site key on the WordPress site, I get "Invalid site key for the current site." But if I try to register the site again on wp-types.com, it says the site is already registered.
same issue for me - After website stopped allowing updates to go through due to it reporting that the site wasn't registered (even though it's been registered since 2014) I tried deleting and re-adding a new site code with a message in wordpress of 'Invalid site key for the current site.' (copying and pasting the code)