In previous times the caption package tried to ensure that it stays compatible with the KOMA-classes. It detected the class and then adapted some of its commands. If KOMA changed something caption tried to follow.

But some months ago the maintainer of caption announced that he will no longer maintain the caption package. Therefore the KOMA maintainer took over and nowreacts to the loading of caption in order to then establish compatibility itself.

So the caption package should continue to work fine with KOMA, if there is a problem you can report it to the KOMA issue tracker (I found one a few days ago:https://sourceforge.net/p/koma-script/tickets/98).

One side effect of the policy change is that caption warns you that KOMA has changed and is now "unknown" (which is true) but as long as you do not get wrong output or errors, you can ignore that.

The warning is generated by the lines 51-55

\caption@ifdocumentclass{unknown}%  {\caption@WarningNoLine{%     Unknown document class (or package),\MessageBreak     standard defaults will be used}}%  {}

of the filecaption.sty.

You can preventcaption from trying to detect the class and force the standard defaults with

\def\caption@documentclass{standard}%

before\usepackage{caption}.

Example:

\documentclass{scrartcl}\makeatletter\def\caption@documentclass{standard}%\makeatother\usepackage{caption}\begin{document}Test\end{document}

You could try

\def\caption@documentclass{koma}%

or

\def\scr@caption{}

to forcecaption using the settings for KOMA-Script classes (caption detects the KOMA-Script classes by testing if\scr@caption is defined). This will load the filecaption-koma.sto and raises the error

caption-koma.sto:90: LaTeX Error: Command \@setcapindent undefined.

showing that currentcaption support for KOMA-Script classes is obsolete.

• captions
• koma-script