Re: t1.enc.def

tex-live list isn't really the right place for latex issues:-)

\DeclareFontSubstitution  is defined in the latex format  (line 10367  of
latex.ltx in the current release)
but with no input or log shown hard to guess how it comes to be undefined
in your example.

David


On Sun, 2 Nov 2025 at 20:57, Bob Tennent <[email protected]> wrote:

> I'm getting
>
> texlive/2025/texmf-dist/tex/latex/base/t1enc.def
> ! Undefined control sequence.
> l.49 \DeclareFontSubstitution
>                              {T1}{cmr}{m}{n}
>
> Problem solved by deleting line 49.
>
> Bob Tennent
>