Vanishing mods

[Traehgniw]

Operating System

Windows

Version of Prism Launcher

6.3

Version of Qt

qt 6.4.2

Description of bug

I updated a CurseForge modpack to the most recent version and some of the already-installed mods, that did not have an update, were deleted from the mods folder. This caused the game to not be able to launch. The modpack in question was You Like Food? from CurseForge and this has happened multiple times but not every time.

Steps to reproduce

Download an old version of a curseforge modpack. Launch. Close game. Go to Edit on that instance, click Curseforge, update it. Modlist may have shrunk.

Suspected cause

No response

This issue is unique

• I have searched the issue tracker and did not find an issue describing my bug.

[ColonelGerdauf]

I will semi-confirm this by saying that a number of mods downloaded from Prism's lookup struggle to stay installed.

This bug is truly random, therefore really difficult to reproduce. I know that this happens with for instance Starlight x Create in 1.16.5. I install the mod, and it claims to have installed. I check the folder path, and the mod indeed exists there. But the moment I exit the edit menu and later enter the modlist, the mod magically vanishes.

[Traehgniw]

Ones it has definitely eaten before just from my attempts at playing YLF include Rubidium, Farmer's Delight, Flywheel, Nether's Exoticism, Twilight Forest, Stardew Valley Food, Twilight Delight, Oh The Biomes You'll Go, Placebo, Selene, SophisticatedCore, FTBLibrary, Supermartijn 642 Corelib, Neapolitan, Terrablender, Geckolib3, Patchouli, and Item Filters.

[showierdata9978]

Happened with fabricly optimised, the entire instance was gone. in fact, all of the config was gone for the launcher

[Traehgniw]

It hit a non-curseforge pack of mine too. I updated some mods using the "check for updates" button and when I went to play the game it had eaten at minimum Spelunkery. I don't know if any other mods were affected. Also sometimes it doesn't get rid of the old version of a mod after updating so I end up with 2 copies.

[LoganTheAroAce]

I'm having this issue with ATM9. I really hope the Prism Launcher Devs fix this in the next version.

[Aces-and-Jacks]

Does anyone know if this happens to modrinth or just curseforge?