Turn off the infuriating ability to drag folders into other folders accidentally at the Explorer in Visual Studio Code 1.17.2.

1. go to: File > Preferences > Settings
2. add to the JSON object that appears a line reading:
   ,"explorer.enableDragAndDrop": false

 
 

This is the same place one would set the amount of spaces in tabs also, but do not set that setting. Leave it be at four spaces. Per this the way to do that might be...
",editor.tabSize": 4
,"editor.insertSpaces": true
,"editor.insertSpaces": true