From the research that i found i guess this is a manufacture defect to this year trailer. They didn't install flashing to the sides. unbelievable!!!
I don't think this is specific to your model trailer, I just found ours to be rotted on the ends of the dining room slide from lack of end flashing. Did you repair yours and what was involved? Just returned from a trip to Louisanna and noticed our slide was kicked inward at the bottom and when I started to adjust is when I found this problem. Has anyone else tackeled this issue. Any info would be helpful. Trailer is a 2008 Starwood LX by Monoco. Slide is just over 12 ft, were could you find 12' material for repair? Thank you