[tex-live] Package missing following "Update all installed"

[Philip Taylor (Webmaster, Ret'd)]

Karl Berry wrote:
>      >  ! LaTeX Error: File `l3fp.sty' not found.
>      Advice, please ?
>
> Does e:/TeX/Live/2010/texmf-dist/tex/latex/expl3/l3fp.sty exist?

Yes, it does Karl; the file manager says it was
created yesterday at 16:47.

> If so, remake the filename database.

As it is now reporting a different problem following
a further "Update all installed" (see recent message),
should I still carry out this step ?
>
> If not, try updating from another mirror.

That is less simple than it sounds : I had thought (perhaps
naively) that when I perform a "TLMGR/Load other repository",
I would be presented with a list of repositories from which
to choose.  In fact, I am presented with a "Package repository"
input field, and apparently required to populate that field
by reference to other resources.  This seems a rather odd and
unfriendly way of doing things ...

** Phil.