Menus are disabled and Render Queue window is open in After Effects

When you launch Adobe After Effects,  most menu items are dimmed, and the only open panel is the Render Queue, which is full screen.

Solution: Launch the main After Effects application

You have launched After Effects in the After Effects Render Engine mode by doing one of the following:

• You clicked the After Effects Render Engine icon instead of the normal After Effects application icon.
• There is a file named ae_render_only_node.txt in your documents folder, as described here:
  After Effects Help | Automated rendering and network rendering
  

Additional information

The ae_render_only_node.txt file can be in one of the following locations:

• Mac locations:
  /Users/[user name]/Documents/
  /Users/Shared/Adobe/

• Windows locations:
  C:\Users\[user name]\Documents
  C:\Users\Public\Documents\Adobe