Note 03/12/2019 - This post has been updated to support changes in 1901 TP and (I assume) 1902 CB to the TSProgressUI.exe ConfigMgr client component used for the custom described dialog below. Note: You must be running ConfigMgr/SCCM 1810 or higher to use the _SMSTSLastActionName variable included in this post. However you can use the same concepts and error dialog with previous versions (but seriously, upgrade already!). Also, go upvote the UserVoice item to have the product do this natively.
