We've found that sometimes the generation jobs for AEM Sites in Guides will get stuck (we are guessing due to some parsing error when it is generating pages), so eventually you need to cancel the job. However when you cancel the job, it stays in "Cancelling" mode and never actually cancels. You can see them on the Publishing Dashboard as well and again, you can't get rid of them, no matter how many times you click the "X" icon. This also starts to cause problems generating new jobs as they just sit in "Waiting" status and won't generate pages.
