Problem with expl3.sty

[Joseph Wright]

On 25/04/2023 21:30, Karl Berry wrote:
>      This error usually happens because TeX Live sometimes creates local
>      format files when updating, and "forgets" to regenerate them
>      ...
>      https://tex.stackexchange.com/a/598609/134574
> 
> As far as I can think of, install-tl/tlmgr never creates "local" format
> files, despite the statements in that tex.sx post. Users have to
> knowingly create them themselves by running fmtutil-user. Am I wrong?
> Anyway, it would be wrong for tlmgr to update them. The advice in that
> post to remove them is usually what is desired. --best, karl.

We've seen this repeatedly, with some users who definitely know what 
they are doing ...

Joseph