Depending on the formatting for the title page of each PDF file, there may be some circumstances in which Elicit is unable to identify the paper's title, authors, or abstract correctly. Additionally, if you upload a .ris or .bib file of sources, not all of the sources may include an abstract, which would result in a metadata only paper record in your Library, which can't be included in a workflow.
You can adjust the paper's title or author(s) as well as edit or add an abstract by clicking on the paper's row in the Library table and clicking the pencil icon to edit:
You can add or change the title, add, remove, or edit author names, and add or edit the abstract:
When finished making your edits, be sure to click the Update button.
Note: Changes to a paper's title, author(s), or abstract must be made before including it in a workflow, at this time. If a paper has already been included in a workflow, edits to the paper details in the Library will not be reflected in that workflow. Edits would apply to any new workflow created in the future.