Version v2.3 (2022/01/07) of `caption3` has introduced a bug in `floatrow`. Indeed, the following MCE (which involves `caption3` only indirectly): ```latex \documentclass{article} \usepackage{floatrow} \floatsetup{capposition=beside} \begin{document} \begin{figure} \centering Foo \caption{Bar} \end{figure} \end{document} ``` fails to compile with the error: > ! Package caption Error: Undefined position `a'. And, indeed: - line 1030 of `floatrow` contains `\caption@ifinlist{#1}{beside,side}{\caption@setposition{a}\capbeside`, - line 929 of `caption3_2020-07-29.sty` which contains `\caption@ifinlist{#1}{a,auto}` has been dropped in `caption3.sty`. Could advise a replacement of `\caption@setposition{a}` in `floatrow.sty`? If you see other adjustments needed in `floatrow`, please advise as well :smile: (though I'm not sure its author, Olga Lapko, is still active). Here is my *File List* ``` article.cls 2021/10/04 v1.4n Standard LaTeX document class size10.clo 2021/10/04 v1.4n Standard LaTeX file (size option) floatrow.sty 2008/08/02 v0.3b floatrow: float package extension keyval.sty 2014/10/28 v1.15 key=value parser (DPC) caption3.sty 2022/01/07 v2.3 caption3 kernel (AR) l3backend-luatex.def 2022-02-07 L3 backend support: PDF output (LuaTeX) ts1cmr.fd 2019/12/16 v2.5j Standard LaTeX font definitions color.sty 2021/12/07 v1.3c Standard LaTeX Color (DPC) color.cfg 2016/01/02 v1.6 sample color configuration luatex.def 2021/06/01 v1.2c Graphics/color driver for luatex supp-pdf.mkii ```