This update is from our 2.2.1 versions we pushed out on Tuesday, October 13th, 2020. You can see the announcement here https://pixelexit.com/threads/2-2-1-style-updates.12393/
This was an update which we released on May 31st. You can view the full update notes here: https://pixelexit.com/threads/2-1-10-style-updates.11887/
This notification is to get the XF Resource Manager up-to-date.
This is a rather large style update that brings new features, improves compatibility for third party plugins, and also squashes some bugs!
It's very important you read the official announcement thread for this update prior to upgrading. You can view the thread here https://pixelexit.com/threads/2-1-8-style-updates.11646/
With an active license you can download the update here https://pixelexit.com/products/purchases