This has happened to me as well, and was very perplexing for quite a while. The bugs dissapear when the files are open, but reappear when the files are closed. I checked the syntax in the HTML source code, but nothing came up that would get rid of the mysterious bugs. Finally, I happened to notice that there was a duplicate line of HTML that referred to a component I was using in my files. One of them had the wrong file path even though the syntax was correct. Once I deleted the duplicate line of code, the bug disappeared. This has worked for all of my buggy files. A friend tried this sucessfully as well. Hope it works for the rest of you who have gotten used to seeing those nasty little green things!