Late game bugs with placement (on multiplayer + with mods)

[clusterfack]

Factorio revision: 0.14.22

Background
I've been playing modded multiplayer games on a headless server with friends, the mods I've been playing with are bob's and angel's along with a few quality of life mods so it's possible this is caused by them, but it might not be since it is related to a lot of placement behavior.

We have been playing the mods for 2 full days now, my first issue came up about 1 day and 8 hours in, and the second one started at the 2 full day mark.

These issues have ONLY affected me within our multiplayer playthrough, with 4 of us playing. We also had our first desync shortly after these bugs started occurring.

Issues
1. Placing objects causes the placed objects to despawn a second later. This started occurring first at about 32 hours into the game.

Placing an object down of the same type repeatedly will start it on a cycle of immediately picking back up the object or deleting it. This can even allow the user to instantly remove any object that can be placed on, say if you place a conveyor belt on a conveyor belt, it will replace the conveyor belt and then remove the one you placed.

This is temporarily fixed by placing one object of a different type down. After you place down an object of a different type the bug resets temporarily, but will eventually resume again within about 20 placements. This did not seem to affect rail placement using the rail placing ui.

2. All objects not being placed where you placed them. This started occuring about 48 into the game.

Here is a video of this in action: http://puu.sh/v6UCk/7dd836782a.mp4

In this bug, objects seem to be "snapping to an unseen grid". Here, when placing the rails they will move vertically or horizontally to snap to some unseen grid. Here is a picture of me having placed rails randomly throughout this area, the rail locations are NOT where I placed them but where they snapped to: http://puu.sh/v6WLB/8c019942ca.jpg.

There are two horizontal strips of rails because the grid apparently shifted when it started snapping to the vertical grid, and the lower horizontal strip started being placed after swapping back to snapping to the horizontal grid.

I later reproduced this with other objects as well such as turrets.

Factorio-current.log from the game
http://puu.sh/v6XKQ/ff2b08d227.log
Factorio-previous.log
http://puu.sh/v6XNZ/912a0ee51f.log
Desync report for desync that occurred just after these issues started
https://www.dropbox.com/s/kz8gy7vtgmj38 ... 6.zip?dl=0

These bugs are extremely bizarre and possibly caused by mods, though I don't know far the modding API goes to see if this could be a result of them or not thus a bug report seemed appropriate.

[Loewchen]

Considering your latency, this is completely expected behaviour.

[clusterfack]

I could understand things being despawned being a result of latency, but being placed on invisible lines?

[clusterfack]

Okay, to disprove the notion that this was latency related I saved the file and loaded it up on my singleplayer server. These issues still occur playing locally on a file saved from the server.

Issue occurring again
https://puu.sh/v6ZiI/421d6d6ec6.jpg
Factorio-current.log after playing locally
http://puu.sh/v6Zno/b75930288c.log
Save file (this only occurred for me, even when playing multiplayer so I don't know if it could be any help)
https://www.dropbox.com/s/v8l6028bmd3ts ... j.zip?dl=0

[Rseding91]

Okay, to disprove the notion that this was latency related I saved the file and loaded it up on my singleplayer server. These issues still occur playing locally on a file saved from the server.

0.800 Loading mod CursorLock 1.3.0 (data.lua)

Adds a hotkey to lock and unlock the build cursor to the x and y axes. Especially useful with mods that extend player reach.

I guess the moral of the story is: don't use mods you don't understand if you don't want weird behavior

[clusterfack]

Ha! That's what happens when you let friends choose the modpack. I had just finished a fresh install to try to remove the problem.

[clusterfack]

Fingers crossed that it also keeps anything from despawning once we remove it.

Edit: yes it seems this mod also caused the despawning to occur, it doesn't play well with multiplayer.