Created attachment 168871 [details] error 500 An "Error 500" prevents the holding table to appear in UNIMARC installations. See the capture (made on biblibre sandbox) GET https://staff-mainuni.sandboxes.biblibre.eu/api/v1/biblios/4905/items?&_page=1&_per_page=20&_match=contains&_order_by= 500 (Internal Server Error)
Can you take a look at your server logs to locate the full error message?
I se nothing special in the sandbox's logs
Verified it was just bug 35896 -> https://gitlab.com/koha-community/koha-misc4dev/-/issues/76 by sneaking into your sandbox and giving that bib's item a valid itemtype. *** This bug has been marked as a duplicate of bug 35896 ***
Thanks, so I see it's linked to https://gitlab.com/koha-community/koha-misc4dev/-/issues/76