I am using Visual Studio 2013.
For some reason, the Start Debugging button is missing on my toolbar. Also, when I am debugging, the Stop debugging/Pause buttons are
I had this issue in Visual Studio 2019, and found that the controls were still present, but hidden in the list highlighted below.
Clicking the highlighted arrow allowed me to view the missing controls. By grabbing the dotted handle to the left of the arrow, I was able to drag the controls to another part of the menu until they were viewable.