i always fail the witcher side quest

[Ryan]

whenever i talk to researcher i fail the side quest

[RIOT|Stalkermaster]

Did you look for the scribbles on wall?

[Greb]

There's a bug aparently, and possibly might even be effected by mods.

Only suggestions I have for you are temporarily remove any mods you might have, ensure your unity with the Gajalaka is high (mine is Level 5) as well as ensuring you have fully completed all the Grimalkyne questlines, especially the Gajalaka questline - this means translating all Grimalkyne tracks across all zones, etc.

You raise Unity with each specific Grimalkyne tribe by doing quests in solo and finding them hanging out on the map, then hiring one of their members etc (not player Palicos you find randomly)

If it's not a bug and just tied to your Grimalkyne / Gajalaka progress, then good - you're not locked out of the quest. Otherwise...best wait for more info, or a potential Capcom fix.