My issue appears to be the same as that documented at
89.3 changed the error message from Error: open : no such file or directory
to Error: could not determine content directory for …
Not seeking further de-bugging assistance on this, with a couple work-arounds having been suggested, including downgrading to 88.x. Just flagging that a new failure appeared in 89.x across my different computers and Hugo sites, without my having changed their configuration. That suggests to me that something broke in 89.0 with the archetypes changes referenced above, or (if you don’t want to call it “broken”), there was a behavior change that’s not yet very clearly documented.