After looking at some errors, I see that Typst actually tells you about it:
error: failed to parse YAML (CSShistory.type: unknown variant video,, expected one of Article, article, Chapter, chapter, Entry, entry, Anthos, anthos, Report, report, Thesis, thesis, Web, web, Scene, scene, Artwork, artwork, Patent, patent, Case, case, Newspaper, newspaper, Legislation, legislation, Manuscript, manuscript, Post, post, Misc, misc, Performance, performance, Periodical, periodical, Proceedings, proceedings, Book, book, Blog, blog, Reference, reference, Conference, conference, Anthology, anthology, Repository, repository, Thread, thread, Video, video, Audio, audio, Exhibition, exhibition, Original, original at line 2 column 9)
From it, it’s clear that video, is not video nor Video, therefore the comma is causing the error.
Did you see this error?
Now (soon™) it will also show the point at which the error occurred in the YAML file.
error: failed to parse YAML (CSShistory.type: unknown variant `video,`, expected one of `Article`, `article`, `Chapter`, `chapter`, `Entry`, `entry`, `Anthos`, `anthos`, `Report`, `report`, `Thesis`, `thesis`, `Web`, `web`, `Scene`, `scene`, `Artwork`, `artwork`, `Patent`, `patent`, `Case`, `case`, `Newspaper`, `newspaper`, `Legislation`, `legislation`, `Manuscript`, `manuscript`, `Post`, `post`, `Misc`, `misc`, `Performance`, `performance`, `Periodical`, `periodical`, `Proceedings`, `proceedings`, `Book`, `book`, `Blog`, `blog`, `Reference`, `reference`, `Conference`, `conference`, `Anthology`, `anthology`, `Repository`, `repository`, `Thread`, `thread`, `Video`, `video`, `Audio`, `audio`, `Exhibition`, `exhibition`, `Original`, `original` at line 2 column 9)
┌─ a.yaml:2:8
│
2 │ type: video,
│ ^
help: error occurred in this call of function `bibliography`
┌─ a.typ:1:1
│
1 │ #bibliography("a.yaml")
│ ^^^^^^^^^^^^^^^^^^^^^^
Your file is actually not a valid YAML, as a tool like yq says
Error: bad file '-': yaml: line 6: did not find expected key
And GitHub - redhat-developer/yaml-language-server: Language Server for YAML Files also shows the error:
Not sure if it’s a not-so-hard error or if Typst softens the validation.