Describe the bug
Every time I tried to connect backend, the terminal gave the feedback:
"
INFO: 127.0.0.1:54447 - "GET /apps.json HTTP/1.1" 404 Not Found
INFO: 127.0.0.1:54447 - "GET /templates.json HTTP/1.1" 200 OK"

"Error

Widget errors:

FOMC Document Viewer (economy_fomc_documents_federal_reserve_obb):

[params]: Endpoint param with { roles: ["fileSelector"] } required for multi_file_viewer."