aknowledged AI desyncs in short SP replays - all DCS versions after 2.9.13.68180

[Katmandu]

I have two versions of DCS installed: 2.9.13.68180 and the most recent one. I have two separate Saved Games/DCS folders, so there is no untoward overlap between versions. I have tested all versions since 2.19.13.

2.9.13.68180 replays work perfect.

Every single version after 2.9.13.68180 (i.e., every version with mid mission save functionality) results in AI desyncing in replays, even in short single player dogfights. My standard test is a dogfight between player's P-51 vs AI Bf-109. It lasts just a few minutes and always results in AI desyncing and going off script (the player's plane continues to fly like it actually flew). Example track is attached. 

 

AI desync.trk

Edited September 17 by Katmandu

[Katmandu]

Same problem in the latest version 2.9.18.12899. I've flown a quick guns only mission in Mig-29G against AI Su-27 and the AI in the replay desynced all three times that I have flown this short mission. The player's plane is still doing what it did, including landing at the end, but the AI went rogue every single time. Replays attached.

The other installed version 2.9.13.68180 still has perfect replays (I use separate SavedGames/DCS folders, so there is no interaction between the two versions).

 

 

desync AI Mig29 replay.trk desync AI Mig29 flight.trk

[Nealius]

AI decisions/actions aren't recorded. The AI is still "alive" in the replays. Essentially the only thing being replayed is your aircraft. 

Edited August 14 by Nealius

[BIGNEWY]

Hi, 

track replays essentially record your inputs however AI can behave differently, depending on what they are doing.

 

[Katmandu]

The problem continues with the latest 2.9.20. A simple 1v1 duel with AI - my P-51 vs AI Bf-109 - desyncs very quickly. Replay attached.

The other installed version 2.9.13.68180 (the last version that had good replays, also the last version before mission state save was introduced) continues to have perfect replays. I use separate SavedGames/DCS folders, so there is no interaction between the two versions.

PS Did a few more 2.9.20 1v1 duels with piston and jet fighters, desync rate is something like 80-90%. I attach another set of replays.

desync AI p51 replay.trk

desync AI Mig29 ver2.9.20 flight.trk desync AI Mig29 ver2.9.20 replay.trk no desync AI F18 ver2.9.20 flight.trk

Edited September 17 by Katmandu

[Katmandu]

New version, same issue: simple Single player 1v1 guns only vs AI and it desyncs very quickly. Here are the tracks for the flight and for the replay.

 

desync AI p51 ver2.9.21updated replay1.trk desync AI p51 ver2.9.21updated flight1.trk

[draconus]

On 10/22/2025 at 11:44 PM, Katmandu said:

AI and it desyncs very quickly

Read again previous answers. AI is not synched at all in the track replay. This is by design.

[BIGNEWY]

On 10/22/2025 at 10:44 PM, Katmandu said:

New version, same issue: simple Single player 1v1 guns only vs AI and it desyncs very quickly. Here are the tracks for the flight and for the replay.

 

desync AI p51 ver2.9.21updated replay1.trk 6.86 MB · 1 download desync AI p51 ver2.9.21updated flight1.trk 10.18 MB · 1 download

Hi, 

as mentioned above the AI can behave differently in track replays, when we have time for redoing the replay system I hope it will be more of a review system rather than a debug one, but I have no news to share currently, the teams are to busy with other huge tasks. 

[Katmandu]

On 10/27/2025 at 8:12 AM, draconus said:

Read again previous answers. AI is not synched at all in the track replay. This is by design.

Read again my original post  In DCS version 2.9.13.68180 replays work perfect with no AI desync. The problem only appeared after ED introduced mid mission save states. It's a new bug that I am reporting, not asking for new features.

On 10/27/2025 at 8:35 AM, BIGNEWY said:

Hi, 

as mentioned above the AI can behave differently in track replays, when we have time for redoing the replay system I hope it will be more of a review system rather than a debug one, but I have no news to share currently, the teams are to busy with other huge tasks. 

Thanks for the answer! As I've answered above, I think there is some misunderstanding, I am merely pointing to the fact that AI desync in replays started happening after DCS version 2.9.13.68180, so in all versions starting with 

DCS World

RELEASE

2.9.14.8222

03/19/2025

MISSION STATE SAVE, 2 NEW CAMPAIGNS, HOTFIXES

Therefore it's a bug, i.e., a conflict of mission save state and replays (specifically AI in replays).