Impossible to create document record

Summary:

Impossoble to create document record

Content (please ensure you mask any confidential information):

Hi experts, we want to create a document record for some employees, and we've created an HR custom role that allows to see the document records quick action and select the desired employee for whom I want to upload the document. However when I click on the add button, I complete the requested fields, then it is impossible to save it. Am I missing some privileges? This happens for any document types available, so no restrictions have been applied to the doc types. Thanks a lot.