Forest River Roof Leak

I have a 2001 Forest River Sierra travel trailer that has a ruined roof. Upon inspection, I was told that the top rails were never sealed and this caused the water to seep in and soak the wicking under the vinyl roof. I have heard that this was an issue with Forest River travel trailers from 1999 to 2002 models. Has anyone else had this problem? Was it resolved? Any suggestions?