Is there any way to remove stress lines from a cake. I had to move it and now I have thin lines on. I had it so smooth.

You can try gently patting them with your finger but that hasn't worked for me. What has worked is adding cake sparkles to the surface. They reflect the light and make the little stress lines much less noticeable. Wilton sells some clear ones but they come in a lot of different colors.

To prevent the lines, you may want to use a more supportive board. Double or triple them if you have to