Crash when hiding DataTable window and saving in DataTable Editor

When adding rows to a DataTable that has its DataTable tab hidden or exited out, the Editor will crash when adding a row to the DataTable. This crash happens in 4.17, 4.18, and 4.19.

1. Open a blank project in UE 4.18.1
2. Create a structure blueprint
3. Create a DataTable based off of that structure blueprint
4. Open the DataTable
5. Add rows and close the DataTable tab
6. Save and exit DataTable editor and then reopen it
7. Add a row

Result: Editor crashes

Expected: It adds the row