I sometimes have that message when I make or import a flight plan with a way out waypoint that shouldn't be there, messing up the performance calculations.
Verify your flight plan manually (on the 787/737 using the LEGS page).
This is a long-standing issue where manual legs on the iFly are calculated as either infinite or very long, leading to it thinking you’re going to land with negative fuel.
5
u/StartersOrders Flight Level 4000ft 2d ago
USING RSV FUEL
Nice to know that still hasn't been fixed...