I am suspecting a bug with the JSON keys of exported list of ngrams (Node List/Terms):

we got maybe an inconsistency here : "bfmtv": { "root": "@bfmtv", "parent": "@bfmtv", "size": 1, "list": "MapTerm", "children": [] }

Here the key "@bfmtv" is not in the exported list in fact.

The initial error message I am trying to debug is the following: FatalError {fatalErrorMessage = "[Garg.API.Ngrams.Tools] filterWithRoot, unknown key: @bfmtv"}

Can you make a first test with @,# charachter and eventually fix the export function if it is relevant ?

This issue is linked with the following : purescript-gargantext#551 (closed)