Ahh I think I figured out what the problem was
It would use strpos to see if it the associate or whatever id is already in the url to know whether its rewritten already or not and if the box was empty, php gave a warning message
So I made it only do a strpos if those boxes are not empty.
Also I have added DE to the list
It also does modifications only if it can find the url
Hopefully that will fix it I am about to re-upload the product in a minute