I purchased another year of Pro, saved it and now I get …
The following plugins are out of date: Events Calendar PRO 3.9.3. All add-ons contain dependencies on The Events Calendar and will not function properly unless paired with the right version. Learn More.
That message is telling you there is a no version of Pro to update to. The lastest version is now 3.11.
Both the Events Calendar and the Events Calendar Pro should be on 3.11 to make the message go away.
You can use the auto update feature if you have entered your license to update or manually update by downloading the latest version from your account here on theeventscalendar.com.