'Enter a valid "slug" when importing iiif

(ENV) kermorvant@arius Images % arkindex upload iiif-images  esposalles_list.txt 42ab0534-1816-4b11-a0e9-02c543f9e9b3 --group-prefix-delimiter '/' --group-folder-type folder
Created import folder 'IIIF import' in corpus 'Public | Esposalles'
Processing https://iiif.teklia.com/main/iiif/2/esposalles%2Fb010%2F170025120000003_0472.png
Retrieved an existing image on Arkindex - 'e07526b8-416c-449c-a86c-86bb3bb3675d'
Failed creating esposalles%2Fb010%2F170025120000003_0472 'folder': 400 - {'type': ['Enter a valid "slug" consisting of letters, numbers, underscores or hyphens.']}.
Aborting.

folder est créé par défaut, donc existe bien

esposalles_list.txt