Autopilot failed on long haul flight... again

[nvmbr]

Flying EGLL to KJFK. A little over 3 hours into the oceanic portion of the flight and for whatever reason, the heading selector switched out of managed mode and into selected mode but not really. I could turn the heading dial but the aircraft didn't respond. I tried pushing the heading select button in and the ND would blink for a moment but it would not go back to managed mode. I tried DIR to the next waypoint but that didn't work either. Tried turning AP off and back on, still didn't work. No WASM crashes in debug console. The only option was to fly the remaining 3+ hours manually which is obviously not going to work. 

Nothing had changed in the flight, no recent alt or mode changes. It was following the flight plan until this. The last error in the console was some FuelSystem bug that happened > 1 hour prior to this incident.
 

This is the second time this has happened to me. The first was during an approach and I posted the bug in this forum. This "long haul" aircraft has been out long enough that it shouldn't still have these kind of bugs! 

Autosaves attached
YouTube video of this bug: 

I'm on the latest update for the A350 as of today, 10/5/2025. 
Windows 11
MSFS2020
7800X3D
7900XTX

 

1759610164.bin 1759610618.bin 1759611066.bin

[Simon Stühlinger]

Flightdirector is off?

[nvmbr]

29 minutes ago, Simon Stühlinger said:

Flightdirector is off?

Yep, FD turned itself off and I was not able to turn it back on which is part of the bug. Even still, I should have been able to control the aircraft heading in selected mode from the FCU. The video shows that the numbers in the FCU do change but the aircraft doesn't actually respond. 

[Simon Stühlinger]

Ok.so do you try to delete the WASM folder? I get after update a wasm crash on final with all instruments frozen.After that i delete the folder and rebuild it and for bow no problems so far