BLS 2017 v 29.03.07 - 3 Different Centers with 3 Different Operating Systems (Win Server 03, Win 7 and Win 10) Have the same issue on all.
When adding/changing graphics to the league standing sheets the Remove Image, Image Properties, Move to Front and Move to Back buttons are inactive. The only button that is active is the Add Image. Which does not allow the removal of a image.
There is a workaround. You can right mouse click on an image and click on properties, which takes you to the screen to where you can remove the image or modify it.
Anyhow just thought I would bring this to your attention!