If you are potentially waiting three days for this to complete then you may not want to interrupt that to verify and correct these
If you scrape-n-paste your expression from your screen into a notebook then, with a bit of hunting, it shows that
You have Cos[θ] ] that should probably be Cos[θ] OR maybe that hints that when you were scrape-n-pasting your expression to make you post that some part of your expression was lost. That would be much worse.
You have [Mu]y that should probably be \[Mu]y OR again perhaps some part of your expression was lost.
Carefully checking and fixing those should help anyone who wants to scrape-n-paste this off their screen into their notebook to try to help you.
