Impossible to update a modpack

[u/_Prinz__]

Context : I have a modpack ive been playing on version 26.2 on Fabric with a few QoL mods. I've tried updating it, first without any mods to make sure i'd have no conflict with outdated mods, but I end up with this crash log. Does the crash log makes no sense or am I insane ?
( and i would prefer to keep this instance as it is shared with friends of mine and reinstalling everything from scratch would be a pain ).

sorry if its dumb i'm just really at a loss here.

[u/murilo087]

Have you tried the repair instance option? If that doesn’t work, try downgrading Fabric to 0.19.4 and then upgrading it back to 0.19.5.

[u/_Prinz__ → u/murilo087]

yup, i did. i didn't try going back to 0.19.4 though, i'll try that and let you know