I'm not really sure if this a recent regression, or something already present in the frontend, but while working on this backend ticket, I have tried importing some Terms from the usual UI:

To my surprise, it looks like the frontend is calling this endpoint:

https://dev.sub.gargantext.org/api/v1.0/lists/188870/csv/add/form/async/

However, this endpoint doesn't exist anymore -- the only endpoint we support is /api/v1.0/lists/{listId}/tsv/add/form/async (as you can see from the swagger docs ).

Therefore, the backend would reject the request with a very unhelpful message:

Only GET or HEAD is supported

I think the solution is quite simple: the frontend should be amended to call the correct endpoint.

Self-assigning this to me as I'm working on the relevant backend issue already.