Some bikes are delivered with a fault where the brake light is permanently on. A trip to the dealer to fix is the usual response. One report was traced to a faulty ABS sensor which requires removing the tank for access.
Suggestion from Askar Aiteliyev on the Facebook group KTM 790 Adventure : “High pressure in the ABS line, make short 10 min trip with short braking front and rear. Will be fixed. Same will be done by dealer.”
A few of reports (one by Andy Thomas on the Facebook group KTM 790 Adventure, another here) of liquid leaking from the standard exhaust staining everything. Probably condensation water. But the leak is not normal there, the exhaust should be sealed. Trip to the dealer for a fix.
Early bikes had a white residue deposit in the fuel tank. Probably some wax leftover from manufacturing. Extreme cases can block the fuel filter. Wax floats, if you fill your fuel tank and see white flakes at the surface get the bike to the dealer for a cleanup and filter change under warranty.
Apparently this is affecting only known serial number and KTM is asking dealers with the affected bikes to remove the tank and clean it, with a picture send to KTM to prove they did it. No customer should experience this at this point.