Decided to turn off the SDK after a long time, to see if I am still being affected by this, and it seems I am. Flew a short distance along the Florida coast, and confirmed the flight appeared in the sim logbook, and in Flightlog Analyser. I shut the sim down, and restarted it, and the flight was missing from the sim.
Flight 73 is missing.
After a cloud reset failed to fix this I 100% gave up on relying on the internal log book. I did the reset a couple of months ago and it appeared to work for perhaps 6 hours of flights then flights started to vanish again. Since the reset I have 80 something flying hours yet the log book only shows just over 30 hours, meaning over 50 hours have vanished. I still stand by my theory that it is linking to the cloud syncs.
Reading through some recent comments I am confused as two moderators state differently with one saying they are struggling to replicate the problem and another saying yes they can. If Asobo can then surely it should be bug logged.
Surprised given the large amount of people who have reported it, and that may just be a small fraction who are even aware of it since many may not even look at the log book.
I do understand why itâs sometimes hard to replicate this problem.
Not all flights are dropped from the log all the time.
So, if you try to replicate only once or twice just in while the flights are not beeing dropped, you may not see the problem to occur.
I frequently check for flight to be logged just after it is finished.
Mostly, they are propperly logged.
But after restarting the MSFS 2024, they are sometimes lost.
It might be hard to replicate but it shouldnât be difficult to solve it.
Just donât save the logbook in the cloud and have it stored on the local machine instead and just keep a copy in the cloud (for cross platform flying) but make sure that the local file never gets overwritten by a cloud-backup (especially when it holds less flight than the local copy).
For me, they are lost after a restart every time unless I have restarted the flight after loading in which is what Iâm doing at the moment. If you donât do a restart on a flight, then end it once completed and then do another flight without exiting the sim, the first flight will be gone after a restart but the ones that were done after that first one will be logged
But as Iâve said above, I donât think the issue is necessarily linked to the account because a friend was having this problem on xbox. He then got a PC and used his same account on the PC and isnât getting the problem on that
I believe the logbook entries are stored in your âsaved dataâ file which is on the local machine and synced to the cloud
And the question is, what is taking priority if the âsyncâ is out of sync.
I strongly doubt that the local file is the priority.
After a flight, it shows in the logbook, but after restarting the sim, it is gone
So the simple fix would be, to never let cloud files overwrite local files without user consent.
As I never fly on a different machine, I would know, that my local file is correct and refuse an update.
Others that know, that they recently flew on a different system might want to agree to the update.
At least in early days of MsFS there was a popup asking what data should be used when they donât match.
They could just use this existing logic for the logbook as well.
My experience exactly, although interestingly Flightlog Analyser still shows that missing flight, and it should be pointing at my 2024 logbook.
One thing Iâm hoping to have time to test tonight is what, and when gets uploaded to the cloud. When I performed my test flight, I confirmed the flight was in the sim log book, then immediately shut down to restart. I didnât leave the sim sitting there for any length of time to complete any upload process.
To observe this hidden process Iâm going to use the MITM proxy again, which will decode the HTTPS traffic, and hopefully see some evidence of logbook data being uploaded to the cloud. What I will be looking for are HTTPS POST logs, possibly PUT depending on how theyâve implemented this.
@PilotCentaur736
Whilst Iâve seen this issue occur, please note that I (like the other moderators) am just a regular MSFS user with some extra moderator rights on the forum. Iâm not a Microsoft /Asobo employee.
Jummivana is a Microsoft employee (as are the other Community Managers), so can speak authoritatively for Microsoft. I speak only for myself. 
Presumably that can be manually synced over the top of your 2024 logbook, to restore the flight?
I once synced my 2020 logbook, going all the way back to August 19th 2020, and pushed that into 2024, and it actually worked!
So far I was not able to sync the lost flights back.
Maybe if you delet your profile.
Anyhow I did use the new update around middle of Dezember and figured out I lost about 50% of my flights since then.
Realy wired, since I have seen this I do no longer look at the MS Flightlog. It is kind of useless at this point.
EDIT: You can record live telemetry data during you flight by having it running in the background. Nice feature
So I performed a quick take off, loop back, and land. I checked that the log had appeared in the logbook. Interestingly a flight I did yesterday has been retained.
While I was watching the flight, what I noticed was telemetry is constantly being uploaded, not just logged to a local logbook file for upload once the flight has ended. Because of that itâs a bit tricky to identify the very first entry, but it may be this one:
"CustomTags" : {},
"Events" :
[
{
"CustomTags" : {},
"Entity" :
{
"Id" : "<ID REDACTED>",
"Type" : "title_player_account"
},
"EventNamespace" : "custom.title.C1771",
"Name" : "FlightHeartbeat",
"OriginalId" : null,
"OriginalTimestamp" : null,
"Payload" :
{
"Body" :
{
"AGLAltitude" : "35",
"AircraftHeading" : "31",
"AircraftLatitude" : "8.46848",
"AircraftLongitude" : "-83.59624",
"AircraftPitch" : "0.2",
"AircraftRoll" : "2.2",
"AtmosphericPressure" : "29.8",
"BuildID" : "1.7.7.0",
"BuildType" : "Master",
"CamID" : "2",
"DistanceFlown" : "495",
"EngineRPM" :
[
"2585.5"
],
"EventSequenceID" : "84",
"ExtWnd" : "0",
"FlapsExtension" : "29",
"FlightSegmentIndex" : "1",
"FlightSessionDuration" : "201",
"FlightSessionID" : "ED15B68B-A2FF-4D68-B2AB-37605782BFF9",
"FlightState" : "10",
"FlightViewSeeds" : "BE87F246ABCED81B-D93F27F90C0BA07B-6AFC3264F01484AF-74633002AC932A02",
"Frames" : "39",
"FrqFHB" : "10",
"FuelQuantity" : "43",
"GameBranch" : "LIVE1.0",
"GameMode" : "FREE_FLIGHT",
"GlitchedFrames" : "0",
"GroundSpeed" : "93",
"HitchCount" : "82",
"IndicatedAirSpeed" : "88",
"IsInFlight" : "1",
"IsOoF" : "0",
"IsPaused" : "0",
"LandingGearActive" : "1",
"MSLAltitude" : "35",
"MultiFilter" : "0",
"OutsideAirTemp" : "14",
"PlatformID" : "6",
"PlayerSessionID" : "6F21EE60-A50F-44A2-8B6B-19012247FAC7",
"SandboxID" : "RETAIL",
"SmartCam" : "0",
"SubSessionID" : "2253AC97-EDA2-1ACF-00E3-5BFD151F44E5",
"Tag" : "SIMUPDATE5",
"Teleport" : "0",
"Variants" :
[
"a07cb9"
],
"WindDirection" : "269",
"WindSpeed" : "3"
}
},
"PayloadJSON" : null
}
]
}
You can see your lat/long, pitch/roll, altitude, wind, and other info. Then every second or so there are more uploads, like these:
Iâm assuming this is the information you can see in external tools like Flightlog Analyser, where you can view your flight, and export the KDL information for input into other tools like Google Earth.
So it isnât really a single sync of your flight into the cloud, its many, many little updates, I assume all tied together by the flight session ID:
Itâs not the very last entry, but there is one important one based on the label âBackToMainMenuâ.
"CustomTags" : {},
"Events" :
[
{
"CustomTags" : {},
"Entity" :
{
"Id" : "<ID REDACTED>",
"Type" : "title_player_account"
},
"EventNamespace" : "custom.title.C1771",
"Name" : "FlightSessionEnd",
"OriginalId" : null,
"OriginalTimestamp" : null,
"Payload" :
{
"Body" :
{
"AGLAltitude" : "1",
"AircraftHeading" : "261",
"AircraftLatitude" : "8.48013",
"AircraftLongitude" : "-83.58990",
"AircraftPitch" : "0.5",
"AircraftRoll" : "-0.9",
"AtmosphericPressure" : "29.8",
"BuildID" : "1.7.7.0",
"BuildType" : "Master",
"CLitemAuto" : "0",
"CLitemEvaluation" : "0",
"CLitemForced" : "0",
"CLitemManual" : "0",
"CamID" : "34",
"EventSequenceID" : "109",
"FlightExitType" : "BackToMainMenu",
"FlightSegmentIndex" : "-1",
"FlightSessActiveOoF" : "109",
"FlightSessPauseOoF" : "0",
"FlightSessionDuration" : "272",
"FlightSessionID" : "ED15B68B-A2FF-4D68-B2AB-37605782BFF9",
"FlightSessionPauseDuration" : "2",
"FlightState" : "4",
"FlightViewSeeds" : "1F0A6D40659F8243-8471CFB8660A7FCB-18F024FF27F0C625-565DE95D78F7F0F3",
"FlyingSegments" :
[
{
"Distance" : "6036.14",
"Duration" : "270.33"
}
],
"GameBranch" : "LIVE1.0",
"GameMode" : "FREE_FLIGHT",
"HitchCount" : "84",
"IndicatedAirSpeed" : "0",
"IsInFlight" : "1",
"IsOoF" : "0",
"IsPaused" : "0",
"MSLAltitude" : "23",
"OutsideAirTemp" : "15",
"PlatformID" : "6",
"PlayerSessionID" : "6F21EE60-A50F-44A2-8B6B-19012247FAC7",
"SandboxID" : "RETAIL",
"SubSessionID" : "2253AC97-EDA2-1ACF-00E3-5BFD151F44E5",
"TTSCharTotalV5" : "327",
"TTSLengthTotal" : "10.00",
"Tag" : "SIMUPDATE5",
"TotalFlownDistance" : "6036.14",
"TotalFlownDuration" : "270.33",
"TotalWalkedDistance" : "0.00",
"TotalWalkedDuration" : "0.00",
"Variants" :
[
"a07cb9"
],
"WalkingSegments" : [],
"WindDirection" : "242",
"WindSpeed" : "4"
}
},
"PayloadJSON" : null
}
]
}
So that, or perhaps one after kind of âsealsâ the log entry, completing the upload of data.
After relaunching the sim to check the logbook, todays flight is missing, but the one from yesterday is still there.
This issue is still occuring on my PC in SU5 v1.7.7.0. Here is a screenshot taken on 2/21 (local time):
Then on 2/22. The two previous entries are still there, plus a new entry (U79 to 3U1):
and today. The flight from U79 to 3U1 in the Shock Ultra has been removed:
This is what my Logbook returned to every day no matter how many flights I did.
After the Cloud reset and a bunch of flights it now is working properly but I lost more than 1300 hours way over 3500 flights. Reset happened on Dec. 9, 2025. So far looking better.
The Cloud has messed up other games too that my friends play.
This problem is still present in SU5 1.7.7.0 - to confirm the previous post. I made a short trip, about 40 minutes, which was recorded in the log. I exited the sim, then restarted it to check how long the flight was and it was gone. I hae restarted the sim a couple of times since then, but itâs gone. It was the only flight I made today and it ended in the normal way (i.e. I made a horrible landing 
)
One year later, since SU2 beta, still a thing for me in SU4 (and it appears still in SU5). Still keeping a spreadsheet where I can account for the flights dropped from my logbook, if any of the teams are interested (since they cannot seem to replicate this bug). Not interested in other logbook solutions for myself, and those have been thoroughly discussed above. Cheers!
I usually do a medium-load flight with a PC 12 first, which appears in the logbook. But if I then do a flight with an airliner on a passenger mission on the same day, the first one (PC 12 medium-load) disappears from the logbook.
I lost the passive income too
Itâs crazy as this was the same problem in 2020 version and itâs 2026 now and even now this is an issue, lucky little navmap saves my flight but geez a simple logbook, even that doesnât work well after 6 yearsâŠ
