#9 `unknown \newfloat definition found` warning

[Gustavo Goretkin]

I have downloaded the latest release (koma-script-3586) and tried this document:

\documentclass{scrbook}

\usepackage{floatrow}
\usepackage{scrhack}

\begin{document}
hello
\end{document}

Compilation succeeds, but gives a warning message:

$ pdflatex mwe.tex
This is pdfTeX, Version 3.141592653-2.6-1.40.22 (TeX Live 2021) (preloaded format=pdflatex)
 restricted \write18 enabled.
entering extended mode
(./mwe.tex
LaTeX2e <2020-10-01> patch level 4
L3 programming layer <2021-02-18> (./scrbook.cls
Document Class: scrbook 2021/03/17 v3.33 KOMA-Script document class (book)
(./scrkbase.sty (./scrbase.sty (./scrlfile.sty (./scrlfile-hook.sty
(./scrlogo.sty)))
(/usr/local/texlive/2021/texmf-dist/tex/latex/graphics/keyval.sty)))
(./tocbasic.sty) (./scrsize11pt.clo) (./typearea.sty))
(/usr/local/texlive/2021/texmf-dist/tex/latex/floatrow/floatrow.sty
(/usr/local/texlive/2021/texmf-dist/tex/latex/caption/caption3.sty
(/usr/local/texlive/2021/texmf-dist/tex/latex/caption/caption-koma.sto)))
(./scrhack.sty (/usr/local/texlive/2021/texmf-dist/tex/latex/xpatch/xpatch.sty
(/usr/local/texlive/2021/texmf-dist/tex/latex/l3kernel/expl3.sty
(/usr/local/texlive/2021/texmf-dist/tex/latex/l3backend/l3backend-pdftex.def))
(/usr/local/texlive/2021/texmf-dist/tex/latex/l3packages/xparse/xparse.sty
(/usr/local/texlive/2021/texmf-dist/tex/latex/l3packages/xparse/xparse-2020-10-
01.sty
(/usr/local/texlive/2021/texmf-dist/tex/latex/l3packages/xparse/xparse-generic.
tex))) (/usr/local/texlive/2021/texmf-dist/tex/latex/etoolbox/etoolbox.sty))
(./float.hak

Package scrhack Warning: unknown \newfloat definition found!
(scrhack)                Maybe you are using a unsupported float version.

) (./floatrow.hak))
No file mwe.aux.
(/usr/local/texlive/2021/texmf-dist/tex/latex/graphics/color.sty
(/usr/local/texlive/2021/texmf-dist/tex/latex/graphics-cfg/color.cfg)
(/usr/local/texlive/2021/texmf-dist/tex/latex/graphics-def/pdftex.def
(/usr/local/texlive/2021/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
[Loading MPS to PDF converter (version 2006.09.02).]
))) [1{/usr/local/texlive/2021/texmf-var/fonts/map/pdftex/updmap/pdftex.map}]
(./mwe.aux) )</usr/local/texlive/2021/texmf-dist/fonts/type1/public/amsfonts/cm
/cmr10.pfb>
Output written on mwe.pdf (1 page, 10361 bytes).
Transcript written on mwe.log.

Previously discussed here: https://github.com/fmarotta/kaobook/issues/148

[Markus Kohm]

This only happens, if scrhack is loaded after floatrow. It is recommended to load floatrow before all packages, that should be patched by scrhack.

Nevertheless this is a bug and fixed in [r3602].

[Markus Kohm]

Just a note: scrhack has been removed from KOMA-Script 3.42 [r4076] and replaced by a completely new implementation of several small packages and a compatibility scrhack. See https://github.com/komascript/third-party-enhancements for more information.