That's a shame. Have you been going up there regularly for cleanings and roof inspections? Seems like that kind of damage would jump out at you. Regardless, sad it wasn't installed properly to begin with.
2015 Black F-350 Platinum Diesel Dually Crew Cab
2019 Riverstone Legacy 38MB (Full Paint/All Options)
2015 Voltage 3990 (Full Paint, All Options) Sold 6/18
2005 Harley Ultra Classic w/too many miles
Hard to tell with just one picture. Looks like ROT and MOLD in some spots. Could have been from hitting something or just improper maintenance for a four year old RV roof or it had a manufacturing defect (bit I think or hope you would have caught it before four years). Smily, can you elaborate a little when you cool off a bit?