Factorio Forums

1. Join dedicated MP Server with another player.
2. "My Blueprints" pick a blueprint book with multiple blueprints in it.
3. Make a copy of a said blueprint book and place the copy of the blueprint book into the "game blueprints".
4. Another player on the MP server takes the BP out of the "game blueprints" and moves it to their "My Blueprints".
5. Other player attempts to use that BP book.
6. Results: glitchyness with copied BP book.

Other Player's copy of the BP book is glitched out. It will want to not paste the BP most of the time the preview will always stick to whatever the original selected BP was in the book at the time it was copied from the original player. You can see the Shift+Scroll to change the selected BP will change if for about half a second then it resets to whatever it was originally. If the original player's book operates fine and changes their BP book's selection doesn't seem to affect the copied one. The whole thing is odd. Leaving the server and coming back doesn't fix it either.

The player with the glitchy book can leav and rejoin the server but doesn't fix it. Dunno if a full server restart would fix it or not. I had to export to string then import from string to stop the glitchyness to "fix" it. I've added 2 strings of books that For sure had the issue.

Quick question, in your testing were either player in remote (map) view when trying to use the blueprint book? There seem to be issues with books in remote view unrelated to multiplayer that could be contributing as well.

Potentially related issue: 118438

Does this still happen in the latest version of the game? I don't understand what "glitchyness" means in this context - do you have a video showing the issue?

I'll see if I can still reproduce it in the latest versions. We were just starting to check out the DocJade's AutoRail bp book so I don't think I ever put the BP in my hotbar as we ended up not using it for different reason. I mention this because of the other thread linked.

Setup is you have Player A and Player B on the same multiplayer server.

Player A has blueprint book with some blueprints in it in their personal BP library.
Player A opens the BP book and clicks the "make a copy" button.
Player A puts the copy into the shared Game BP library. Keeping the original in their personal BP library.
Player B takes that copy from the Game BP library and puts it into their BP library.
Player B picks up their copy from their personal library and tries to use their copy to place a BP but it acts all kinds of glitchy. Trying to scroll through the BP will often show the preview of one BP but the name of a different one. Placing the BP will randomly place the BP of yet a different one from the book.
If Player A is holding their original BP and Player B is holding their copy at the same time then Player A can scroll-wheel through their original BP book and randomly affect Player B's BP book selection. Like how is that possible?

It is super strange. It is like there is some internal pointer in the CPP engine that was changed in the copy and still points at the original book somehow. I'm honestly flabbergasted that it doesn't cause an immediate desync or worse.

If Player A or B exports the BP book to a string then Player B imports that string then all is well no issues. Doesn't matter if it was the original or the copy that was used to make the string.
If Player A and/or B leave the server then return the BP book's still seem "tied" to each other.
I never did try seeing if rebooting the server fixes the issue or not. I'd forgotten to do that by the time we got off as I'd already workaround it by export to string and importing again.

While I wouldn't expect it to matter.
Player A is on windows; wanted to play, not debug the problem.
Player B is on linux, is me, the issue sufferer. I, too, wanted to play but also quite interested in figuring out wtf is/was going on.
We were playing on the headless server that I setup and only I have access to.


[edit]
Seems I might have to buy a 2nd copy of factorio to experiment this one. Oh well. Factorio has provided me a decade of fun and I don't see it stopping yet. Worth it. No other game has last me this long or gotten this much play time. I'll gladly own a 2nd copy.

Well I figured out how to run two instances of Factorio at the same time.

I've managed to replicate this in 2.0.10, 2.0.20, and 2.0.24. Just to first prove to myself that I wasn't insane. Jumping to 2.0.72 now. I replicated it the way it originally happened. The huge BP wasn't required for the bug to happen. Seems it happens with any bp book....like test one attached to this post.

Reproduction steps have been:

1. Start with a completely fresh copy of Factorio. No saves, no blueprint library, no nothing for both Player A and Player B.
2. Player A hosts a lan game (any MP mode works for this bug).
3. Player B joins Player A's LAN game.
4. Player A goes to https://factorioprints.com/view/-O9VRJfQs93GnPuihM2B and copies the BP string...or copies the one attached to this post.
5. run cheat command `/c game.player.force.research_all_technologies()` Only needed to enable blueprint shortcuts in the toolbar.
6. [[Not a step but this is where the video starts.]]
7. Player A imports the string into the game.
8. Player A places the imported BP book into their Personal BP Library.
9. Player A opens the BP book and makes a COPY.
10. Player A places the copy into the shared game library.
11. Player B takes the copy from the shared game library and puts it into their personal library. Upon much experimentation THIS IS REQUIRED! If the copy stays in the shared prints I could not get this bug to happen!
12. Player B picks up the "copy" book and scrolls through the book and places some stuff. All is well.
13. Player A picks up their "original" book and scrolls through the book places some stuff. All is well.
14. Player B tries to continue using their "copy" BP book. Nope. It is bugged all to hell now.

When I finally updated to 2.0.72 it was immediately wrong from the moment Player B attempted to use the BP book. on step 12.

Player B's "copy" will continue to be screwed until there is a server restart (that seems to resolve this weirdness) On a dedicated hosted server Player A can leave and Player B's "copy" will still be screwed up.

I think the original comment of mine about Player A being able to affect Player B was a trick. If Player B leaves the server and rejoins there is a delay in the glitchyness for a short bit. While reviewing my video to make sure all was well. around the 1:06 minute mark watch the bp that got pasted CHANGE to a different one after like 1/2 a second. It went from a 3 way to a double U-Turn.