I have previously installed toolset plugin in hidden link. Now the plugin is no longer needed for this website.
When we have deactivated and deleted all plugins related to Toolset, the website still shows the attached error.
When we are trying to activate the plugin again, an error (Invalid site key for the current site) shows.
When we added a new key in our toolset admin page, we got(You've already registered this site before. The site key is: xxxxxx) which is the same key I added before.
How can I deactivate and delete all related things of toolset.
You can simply go to your plugins page and deactivate and delete the plugins as you see fit.
If you're still seeing the message after doing this navigate to Dashboard -> Updates and click on check again and this should clear the Toolset message from your screen.
It seems i'm unable to connect using the VPN. However can you try this method.
Go to Plugins->Add New -> Commercial and from there generate a new key for Toolset and add it to the installer except that you shouldn't install any of the toolset plugins.
Then go to Dashboard->Updates and click on the check again link. Once you've done this go to Plugins and see if the notice still remains. If it is not there then you can go ahead and go back to Plugins -> Add New->Commercial and then remove the product key from the Toolset installer.