After reading your tenth cryptic error message, you might be left with the urge to close the Diagnostics tab and never look at it again. We can’t blame you — debugging Facebook tracking can be a nightmare. It’s worth it in the end, though. The time spent fixing errors now will be repaid tenfold in your marketing return on investment. That’s why we’ve collected a list of the top four Facebook errors. Each error has an explanation of what it means, why it’s happening, and instructions on how to fix it.