Thanks very much for your answer and the corrections made to the ELCD database format. The database can now be imported and updated in OpenLCA without any problem!
I'm still having issues with the OpenLCA LCIA methods v2.1.3 in JSON-LD format though.
The zip folder downloaded on OpenLCA Nexus appears in the Download folder of my computer but not when I go looking for it from OpenLCA (File>Import>Other>Linked Data (JSON-LD)>From directory>Browse).
When I first unzip the openLCA LCIA v2.1.3 folder, 7 folders appear in the left-hand side panel when I browse in OpenLCA (categories, flows, flow_properties, lcia_categories, lcia_methods, nw_sets, unit_groups) but nothing happens when I double-click on them and I can only click on the “< Back” and “Cancel” buttons of the "Select import files" window.
Would you know how to solve this issue?