I can't upload data from my user_dir in a library


I try to import files from userdir_file in a folder of a library.
I can see all the files (of my user directory) on the library interface. But when I click on Import in the Library menu (Datasets > From User Directory) I have a message on the page: An error occured.

![ScreenHunter_154 Oct. 14 10.13|690x105](upload://n7pbp3YHEzCNCLDRPAYL0MTSN6q.jpeg)

The Developper mode of the browser shows that api/libraries/datasets is called with post data : encoded_folder_id=Ff57ea34061aeee2f&source=userdir_file&path=5.txt&file_type=auto&link_data=false&space_to_tab=false&to_posix_lines=false&dbkey=%3F&tag_using_filenames=true

When I try the api link above, I have this error message in galaxy log: Wrong library id specified, unable to decode.

Do you have an idea of what is wrong with the encoding of the id?
The link library/list#folders/Ff57ea34061aeee2f works. It displays the content of the folder.
I often miss something in galaxy configuration, do you have an idea here?
(I work with 20_05)

thank you