[Vx (6.21.0) - Geoscape] Base Defense + Airborne Skyhawk = Crash + Save Corruption

[Nodrak]

Bug: Alien Destroyer attacks Xenonaught Base while outbound Skyhawk mission results in crash on loading into Skyhawk mission.

Details: Aliens attack Xeno HQ while Skyhawk is assigned to UFO mission.  While assigning base defenders, the game will assign people and equipment in the Skyhawk to the base defense.  Initially I loaded the base defense with the Skyhawk team, but decided it was a bad idea due to a likely crash if someone died in the base defense.  So I reloaded a previous save, got the same chain of events, and un-assigned the Skyhawk team from base defense.  Sadly doing this caused the game to get confused and think the Soldiers were unassigned from all assignments, while also still thinking they were on the Skyhawk.  This is verifiable by loading the save and not accepting Skyhawk mission, and then looking at the soldier states.  There are 8 soldiers assigned to the Skyhawk, but the Skyhawk is empty with 8 empty positions.  In addition, this bug state will grant the 'Full Colonel Squad' achievement due to the confused state.

It is likely possible to 'fix' the soldier state by landing the Skyhawk back at base.

I have included 4 saves files as well for ease of testing.

• Save 77 - Day 147: Before Combat - Save before Skyhawk team mission - Accepting the mission will CTD 
• Save 76 - Day 146: After Combat - Save after Defending base without Skyhawk team.
• Save 75 - Day 146: Before Combat - Save before Defending base
• Save 74 - Day 146: After Intercept - Last save before sending out Skyhawk 

Mods: None (Fresh Vx 6.21.0 save)

 

bug_report_2025-11-08-23h00_lo_6.21.0_unhandled_exception_0.zip Vx_6_21_0_CTD_Saves.zip

Edited November 9, 2025 by Nodrak
filename clarification

[Nodrak]

Update: This bug is critical;  It cannot be recovered from unless you have a save that ends up without a base attack with Airborne soldiers OR you complete the Base Defense with ALL airborne soldiers, and then abort the Skyranger mission. (Which may result in other unrecoverable states).

Details: I replayed the base mission with the default assignments.  Base was defended in 1 turn and took no damage.  7/8 of the default assignments were Airborne soldiers, all 7 were unassigned from the Skyranger 'correctly'.  I manually 'curated' the equipment to prevent issues with Items on the Skyranger be assigned to non-airborne soldiers via some internal priority list.  Essentially, doing everything I can to make sure all back end instance references would be maintained.  The 7/8 soldiers was unforeseen at the time but fortunate; the 8th soldier was still assigned to 'Airborne' but was also missing from the Skyranger!  This soldier is permanently bugged, and will likely crash the game any time it or its equipment is referenced going forward.

• Defending a base will clear ALL soldiers from the Skyranger regardless if they took part in the mission.
• Soldiers that did take part in the mission will return to the base 'correctly'.
• Soldiers that did not take part in the mission, will bug out and cannot be recovered even if the Skyranger aborts and returns home.

This bug alone will prevent any Iron Man attempts.

bug_report_2025-11-09-16h43_lo_6.21.0_unhandled_exception_0.zip

[Chris]

10 hours ago, Nodrak said:

Update: This bug is critical;  It cannot be recovered from unless you have a save that ends up without a base attack with Airborne soldiers OR you complete the Base Defense with ALL airborne soldiers, and then abort the Skyranger mission. (Which may result in other unrecoverable states).

Details: I replayed the base mission with the default assignments.  Base was defended in 1 turn and took no damage.  7/8 of the default assignments were Airborne soldiers, all 7 were unassigned from the Skyranger 'correctly'.  I manually 'curated' the equipment to prevent issues with Items on the Skyranger be assigned to non-airborne soldiers via some internal priority list.  Essentially, doing everything I can to make sure all back end instance references would be maintained.  The 7/8 soldiers was unforeseen at the time but fortunate; the 8th soldier was still assigned to 'Airborne' but was also missing from the Skyranger!  This soldier is permanently bugged, and will likely crash the game any time it or its equipment is referenced going forward.

• Defending a base will clear ALL soldiers from the Skyranger regardless if they took part in the mission.
• Soldiers that did take part in the mission will return to the base 'correctly'.
• Soldiers that did not take part in the mission, will bug out and cannot be recovered even if the Skyranger aborts and returns home.

This bug alone will prevent any Iron Man attempts.

bug_report_2025-11-09-16h43_lo_6.21.0_unhandled_exception_0.zip 10.75 MB · 0 downloads

Thanks. We'll look into this - we appreciate the detailed bug report!