I've released a mod and it seems to be working ok for thousands of people, but I've had 5 or 6 reports of it never starting up.

What should happen is, I have a quest flagged as "start game enabled" with a startup stage that has a Papyrus fragment that executes a startup function. The startup function gives various spells and items to the player, registers a couple of OnUpdate blocks for updates, initializes arrays, etc. I had one person check it out with getquestrunning and they said the quest was running, so it sounds like the startup stage code fragment isn't being executed.

Anyone else have this happen, or know what might be causing it?

I know what MIGHT be causing it ...

If 1000s of people can play it OK, but only a handful cannot, then the three most likely things are:

1. Conflicting MOD
2. Dirty Save ... but that one depends on whether or not your MOD does something to vanilla scripts (and maybe objects).
3. Even more unlikely, but because you're using OnUpdate ... Have you released an earlier version of your mod, did the handful install that version?

I had to change one vanilla script, a fragment attached to the vampire feeding perk, but I switched it to use a new script rather than editing the old one. That shouldn't interfere with this though as it only comes into play when the player feeds. With the most recent report I've had, the person says that it starts up fine if they're starting a new game, which leads me to believe it isn't a mod conflict. So a dirty save maybe? Like somehow the save had a quest with a matching formID that had already executed its startup stage?

At any rate I've flagged the main quest as "allow repeat stages" which might let those that are having trouble use setstage to jump start things. We'll see if it helps after the next update.

That's basically the acid test (though not foolproof) ... if it does not run from a save, but does from a new game, then it's usually a dirty save (either from a previous release of your stuff, or to do with the editing of a vanilla script).

It's a little bit odd to see it if you have not made an amendment to vanilla that effects your quest start, though ... Have you released a previous version?

If not ... There is a chance that - because FRAGMENTS are "random named" by default - another mod has the same script name as yours - You can get around that by using Preferences in the CK and adding a prefix (I forget which tab, but there aren't that many), so that all scripts you make have more chance of being uniquely named

Then it depends on load order of each client (I think) - how Load Order is calculated has changed, which ups the ante a bit for conflicts ... There's a topic on that in the mods forum (linked from a recent post on here too ... but I can't find that now). Last I saw, most Mod Managers weren't complaint with the new way of doing stuff (patch two days ago)

Best of luck ... It's going to be a nightmare, is this ...

I received reports of this problem with the first release of the mod, so I doubt its due to an uninstall/reinstall issue. I have a system in place for updating (the main thread of the program compares the saved version number to a hardcoded one that changes with each update, triggering an update function to run.)

The fragment script is named something like QF_IMCNmain_01002DBB, which seems like it should be unique, but I just renamed it and added the IMCN prefix I've been using for everything.

Making changes to your scripts, and re-releasing MIGHT also give you Dirty Save issues.

It depends how your scripts work, and what they do.

I'm losing sense of what is and is not affected, by it all, to be honest ... but if you're up to it, then there is much info and suggestions in this thread: http://www.gamesas.com/topic/1348833-old-versions-of-mods-conflicting-with-newer-ones/

There's an article on the CK wiki about what happens if you edit a script in an update, I read it while I was planning the mod and based on what it says I'm ok. I've updated 3 times so far, all with heavy changes to existing scripts, and no complaints. No problems there, its fresh installs that are occasionally messing up.

Yeah, I read through that too ... If you followed it then you should have dealt with the issue (afaik)

Well, a fresh install having issues is the opposite to a dirty save (kinda), so at that point you would think that another mod is what is casuing the limited issue for the handful of effected players ... Maybe the other mod works differently for Saved and New Games, which is why you get OK reports for new games?