We use a corp. license on a thousands of machines. We have one group of 300 where we have a provided an addional login for our client. When our client logins they are unable to perform features like blank out screen etc. I think they were able to before we upgrade their remote system to the most current. The hosts are still in the range of 11.xx to 13.xx.
Thank you for posting.
1) If you are not able to use the black screen feature even you sign in with an account associated with a license though, please visit this article.
2) if your client signs in with a free version of an account, unfortunately, a license is required in order to use the black screen.
When using the black screen feature, please make sure to sign in with an account associated with a license.
Hope this information will be helpful for you.