The online racing simulator
#1 - Racon
Split 1 times were removed for all players during race
In the race attached, every player had their split1 time 'undone' on lap 1.

We crossed the split and registered a time as shown on the top-right of the screen. InSim sent an SPX packet for each.

A couple of seconds after the first was set, all of them were undone - no longer showing in the top right for any player.

A couple of players hadn't crossed the split when it happened and they both registered times as they did, but they too lost their times shortly after.

We all continued and LFS behaved as it would have done if we'd physically missed the first split, ie, not registering any further splits or the first lap. (I don't think anyone noticed until the second actual lap was showing as lap 1).

When the first player crossed split1 for the second time, it registered, and everything was as it should be from then onwards. The only difference in the end was that we'd driven four laps but only registered three.

I have splits/laps logged, you can see the effect in the times here. (I store all the splits in a stack until they're written on completion of the lap, so there's an extra split showing too)

Timeline: (in lap times, not replay time)

0:20.93 - First split1 set
0:23.10 - All split1 times undone
0:23.55 - First new split1 set
0:28.91 - New split1 times undone
1:32.84 - First split1 set (on second actual lap) - All OK here
Attached files
AS4Y_race_3L_9R_10F.mpr - 1.6 MB - 59 views
It might be helpful to add the LFS version you (all?) are using. Also, it may be useful at a later date.
#3 - Racon
It was server version E8 at the time of the race, my client version was E12.

I imagine everyone else was using a variety of client versions. I can find out if it turns out to be helpful, but I think it was a host issue rather than client because it affected us all.
** Best answer **
Checking the replay, I caught the packet that set the split times to zero.

There are two cases that could cause this packet to be sent.

Admin (or InSim program) typed:
/zero_all
Or:
/setlap USERNAME 0 (for each user name that got set back to zero)

These are the only places in the code that send that packet.

EDIT: further inspection shows it must have been zero_all as no user name was specified.
#5 - Racon
There were 3 admins there - two of us don't use the command, but one of us had it set to a bind. He uses ctrl-f6 and alt-f1 for other common things, but has alt-f6 set as '/zero_all'. It's infinitely more likely that he confused the key combinations without realising it than that it's a bug that has gone undiscovered this long.

Apologies for the wild goose chase!
No worries, it was nice that I could catch it easily in the replay using a data breakpoint.

FGED GREDG RDFGDR GSFDG