For those struggling with this issue, a workaround is to call "texindy -C utf8" or, if using imakeidx, using "\makeindex[options=-C utf8]" (obviously, as long as your document is indeed utf8). Using XeLaTex/LuaLaTeX also works, because both also force utf8.
For those struggling with this issue, a workaround is to call "texindy -C utf8" or, if using imakeidx, using "\makeindex[ options= -C utf8]" (obviously, as long as your document is indeed utf8). Using XeLaTex/LuaLaTeX also works, because both also force utf8.