Today when I logged into some of the sites with Toolset installed I see the message "You must have a valid subscription in order to get upgrades or support for this plugin. Purchase a subscription or enter an existing site key."
When I go to the license page and click the check updates button it shows the sites as registered. I have tried:
1) un-registering and reentering the site key.
2) un-registering, deleting the site from the Toolset sites page, re-adding it to the Toolset sites page, and registering it again.
3) turning off all other plugins and reverting to the 2017 theme.
4) deactivating and reactivating Types and Views.
I noticed that when I deactivate only the Types plugin that the message goes away from the Views plugin on the plugins page.
I have seen this now on 3 or the 4 sites with Toolset installed. One site does not show the message. I have tried the above steps on a local dev site and an online site.