This seems to be down a missing file in MiKTeX. On my TeX Live system, the document compiles fine with a file list
scrreprt.cls 2012/07/29 v3.11b KOMA-Script document class (report)scrkbase.sty 2012/07/29 v3.11b KOMA-Script package (KOMA-Script-dependent basics and keyval usage) scrbase.sty 2012/07/29 v3.11b KOMA-Script package (KOMA-Script-independent basics and keyval usage) keyval.sty 1999/03/16 v1.13 key=value parser (DPC)scrlfile.sty 2012/06/15 v3.12 KOMA-Script package (loading files)tocbasic.sty 2012/04/04 v3.10b KOMA-Script package (handling toc-files)scrsize11pt.clo 2012/07/29 v3.11b KOMA-Script font size class option (11pt)typearea.sty 2012/07/29 v3.11b KOMA-Script package (type area)inputenc.sty 2008/03/30 v1.1d Input encoding file utf8.def 2008/04/05 v1.1m UTF-8 support for inputenc t1enc.dfu 2008/04/05 v1.1m UTF-8 support for inputenc ot1enc.dfu 2008/04/05 v1.1m UTF-8 support for inputenc omsenc.dfu 2008/04/05 v1.1m UTF-8 support for inputenc babel.sty 2013/05/16 v3.9f The Babel package english.ldf 2012/08/20 v3.3p English support from the babel system germanb.ldf 2008/06/01 v2.6m German support from the babel system fontenc.sty t1enc.def 2005/09/27 v1.99g Standard LaTeX file CJK.sty 2012/05/07 4.8.3 MULEenc.sty 2012/05/07 4.8.3 c70min.fd 2012/05/07 4.8.3 c70min.fdx 2012/05/07 4.8.3where the final two files are in tex/latex/cjk/contrib/wadalab/c70min.fd. With MiKTeX on the other hand I get the same error as in the question. The CTAN directory for CJK seems to contain the appropriate files, so a local installation should be possible. However, I think this should also be reported to Christian Schenk as I don't see why there is the discrepancy with TeX Live.
