Have been dealing with leaks on my 5er for 2 years now. i swear every time i clean it, i find a leak. Every single place that has leaked has been at a silicone joint. It does not flex enough with the trailer and once the seal is broken, it is done for.
Just Monday this week, I remove ALL silicone from around every window as it had pulled away and was leaking. they now have Dicor Non-Sag lap sealant. if you find a leak where silicon is applied, better to remove it and apply something else or you will be revisiting it again in the future. Needless, my door does not have silicone and it isn't leaking and the seal isn't broken at all.
Silicone does NOT belong on the outside of an RV as a sealant. It just isn't up to the abuse. They use it because a $3 tube of silicone is much cheaper than a $13 tube of Dicor.
I'm sure after my next camping trip i will have to seal more areas, never fails.