Hi,
Thanks for using our plugins. I can help out here.
The License has used all the installs means the license is already attached to a website. Since you have a personal license you only get one install to attach it to.
If this is an error or you need to reauthorize the site.
You can remove your license key from your account on TheEventsCalendar.com and then reactive on your site.
To do that, login to your account and go to My Account > License Keys
Click “Disconnect now” next to all the urls and go to your site and add those license keys back.
Let me know how that works out for you.
Thanks