We are currently in the middle of a run, and the weapon damage upgrades keep resetting. We think we have isolated it to only when using the queue for research. The first upgrade works, and then if you ONLY select t2 on any damage tree, the upgrade finishes and it works, but if you queue any other research at all, when the research finishes for the first item in queue, ALL weapon damage and only weapon damage upgrades reset back to t1 complete. If you queue t2+t3, it finishes t2 then immediately resets.

We are using almost the entire Schall's mod suite, with the addition of "what is it used for", "unit control", "miniloader", "LTN", "long and far reach", "liquify science", and "blueprint flipper and turner" on the .X game branch.

Thanks for your report.

First of all, which mod versions are you using?
A player has reported some mod conflict in previous version 0.17.3. I have rewritten the code in 0.17.4, so problem should not be coming from that.

I failed to reproduce your result. I tried playing around with research queue and weapon damage upgrade techs but still did not get what you mentioned. It would be helpful if you can describe in more exact steps (e.g., tech name and exact tech levels) on how to reproduce that.

According to what you mentioned, is the problem only coming when multiple levels of the same tech are queued?

On the tech upgrades, my mods do not have complex scripting on them. I simply add the tech prototypes, which are treated the same as vanilla tech prototypes.
And "migration script" on recalculating tech effects (including unlocking recipes and damage bonus) ONLY applies when mods are added/removed or mod version changes, but NOT triggered when finishing some levels of research.
Therefore, if the problem involves research queuing, the cause is probably not my mods; but likely from vanilla game or some mods using their own tech calculations.
Yet still, more information would be needed to determine the cause.

Does the forum here support screen shots? I don't think so... I just hit refresh on the mods update list, and it says I have the newest version of everything, and we are on the .X branch of Factorio main. All the mods in your list are between 17.2 and 17.6, all the most current version you have uploaded.

LTN 1.10.15
BP flipper and turner 1.0.0
Long and far reach 1.17.1
Miniloader 1.8.3
Optera's library 0.1.7
Liquify Science and Big Fluid Lab 0.0.14
Unit Control 0.1.22
What is it really used for 1.4.3

The bug occurs at any point the research queue is utilized. It doesn't matter what is queued, if anything at all is, all the weapon upgrades except specifically rate of fire revert to after the first research is complete. As long as you research one thing at a time and don't use the queue, everything works.

I have been chatting with someone in the group who is looking through to see if he recognizes anything that could possibly conflict, and at this point he is convinced it is a fluke bug with the experimental branch or some combination of the mods with the experimental branch.

Update - We found the problem. We are running a semi-public server, and we had "starting tech" AND "starting inventory" running, and I had set starting tech to "1" across the board in the options for that mod. I am not sure if it was actually breaking because of the mods, or if it was constantly resetting because of people dying/leaving/joining, but it stopped happening when I deleted that mod folder off the server. I am pretty sure that we could consistently replicate it whenever tech was queued, but it could have been false positives because the joins were fairly frequent.

With your information, I can finally reproduce the result.
Please update Schall Starting Tech to 0.17.3 and it should be fine.
Please notify me if the problem persists or not. Sorry for the inconvenience caused.

The cause is new player joining, has triggered level setting to lower level of the infinite techs.