I've only noticed this so far when I've breed approved horses from the breed approval page and set horses free from the barn>move page. After pressing the button to complete an action, a weird line of code appears at the top of the page.

This screenshot was taken while on my windows laptop. It is also happening on my other two accounts. I don't know much about Java/JS, but it doesn't seem like the code is wrong. It just looks like a check is running and wasn't commented out.

This is only at the top of the page. If I scroll down everything looks normal. The features function fine as well.