Timeline marker is missing

In some cases, the purple vertical bar called the timeline marker may disappear due to possible reasons:

• Your browser's zoom settings. This can be fixed by changing your browser's zoom settings using Ctrl/Cmd and the +/- keys or Ctrl/Cmd and scrolling the mouse wheel button up or down. Recommended zoom settings is 90% - 110%.
• Another way to relocate your timeline marker is to press Stop/Pause (Spacebar) and then hit the Enter button twice. This will reposition the timeline marker at the left-most portion of your project.