If the paper stack transfer guide is not at its home position during boot up, the printer tries to bring it to its home position during POST. Should the printer fail to do this, it will then post the intervention message – “Insufficient space between paper stacks in Tray 3”.
To clear the message, power off the printer and make sure that the paper stack transfer guide is at its home position before powering the printer back on.
Set the paper stack transfer guide in its home position by sliding it in the direction shown by red arrows in the image above.
If the issue persists, search for more information related to this issue or contact support for further assistance.