Hey Ikumi,

I checked and even with 'mgs.exe' not in my path (or any MiKTeX 
executable for that matter) and using 'rungs.exe' I get the following 
postscript error next to any LaTeX math formula (the _region_ log seems 
fine):

"c:/Program Files/texlive/2019/bin/win32/rungs.exe" 
"-dOutputFile=(_region_.prv/tmpPwJxGu/pr1-4.png)" "-q" "-dDELAYSAFER" 
"-dNOPAUSE" "-DNOPLATFONTS" "-dPrinted" "-dTextAlphaBits=4" 
"-dGraphicsAlphaBits=4" "-sDEVICE=png16m" "-r110.579x110.865"
GS>{<</PermitFileReading[(_region_.pdf)(_region_.prv/tmpPwJxGu/preview.dsc)]>> 
setuserparams .locksafe} stopped pop {DELAYSAFER{.setsafe}if}stopped 
pop/.preview-BP currentpagedevice/BeginPage get dup null 
eq{pop{pop}bind}if def<</BeginPage{currentpagedevice/PageSize get dup 0 
get 1 ne exch 1 get 1 ne or{.preview-BP 0.156863 0.172549 0.203922 
setrgbcolor clippath fill 0.733333 0.760784 0.811765 
setrgbcolor}{pop}ifelse}bind/PageSize[1 
1]>>setpagedevice/preview-do{/.preview-ST[count 4 roll save]def dup 
length 0 eq{pop}{setpagedevice}{ifelse exec}stopped{handleerror quit}if 
.preview-ST aload pop restore}bind def /GS_PDF_ProcSet GS_PDF_ProcSet 
dup maxlength dict copy dup begin/graphicsbeginpage{//graphicsbeginpage 
exec 0.733333 0.760784 0.811765 3 copy rg RG}bind store end readonly 
store  (_region_.prv/tmpPwJxGu/preview.dsc)(r)file /.preview-ST 1 index 
def dup 0 setfileposition 555()/SubFileDecode filter cvx exec 
.preview-ST dup dup 555 setfileposition 53()/SubFileDecode filter 
cvx<<>>preview-do
Error: /typecheck in --setfileposition--
Operand stack:
    GS_PDF_ProcSet   GS_PDF_ProcSet   GS_PDF_ProcSet   661 661   661   
608   608   608   555
Execution stack:
    %interp_exit   .runexec2   --nostringval-- --nostringval--   
--nostringval--   2   %stopped_push --nostringval--   --nostringval--   
%loop_continue --nostringval--   --nostringval--   false   1   
%stopped_push .runexec2   --nostringval--   --nostringval-- 
--nostringval--   2   %stopped_push   --nostringval--
Dictionary stack:
    --dict:745/1123(ro)(G)--   --dict:0/20(G)-- --dict:79/200(L)--
Current allocation mode is local
Current file position is 28
GS<10>

Wierd that it does work on your system, but I'm not too worried about it 
as it works fine using 'mgs.exe' as a solution (although it's quite an 
ugly one).

Kind regards,

Pim Remkes

Op 5/21/2019 om 7:27 AM schreef Ikumi Keita:
> Hi Pim,
>
>>>>>> Pim Remkes <pim.remkes@gmail.com> writes:
>> After having done this I had issues with
>> the current version of 'rungs' included in tex live 2019. The issues I
>> got were similar to
>> https://bugs.ghostscript.com/show_bug.cgi?id=698680 if anyone is
>> interested. I was able to fix this (for now) by making use of
>> 'mgs.exe' included with MiKTeX.
> As far as I know, the referred problem was resolved shortly after that.
> On my side, "rungs" in TeXLive 2019 does not cause such trouble, both on
> windows 10 and freebsd 12.  I quote the partial log of the former below.
>
> Maybe your rungs is confused by the two instances of the ghostscript
> executables, namely the one under c:/texlive/2019/tlpkg/tlgs and
> "mgs.exe".
>
> Regards,
> Ikumi Keita
>
> Running `Preview-LaTeX' on `c:/Users/keita/Downloads/_region_' with ``pdflatex  -file-line-error   "\nonstopmode\nofiles\PassOptionsToPackage{active,tightpage,auctex}{preview}\AtBeginDocument{\ifx\ifPreview\undefined\RequirePackage[displaymath,floats,graphics,textmath,sections,footnotes]{preview}[2004/11/05]\fi}" "\input" "{\detokenize{" "_region_.tex" "}}"''
> This is pdfTeX, Version 3.14159265-2.6-1.40.20 (TeX Live 2019/W32TeX) (preloaded format=pdflatex)
>   restricted \write18 enabled.
> entering extended mode
> LaTeX2e <2018-12-01>
>
> ...(snip)...
>
> Output written on _region_.pdf (7 pages, 39759 bytes).
> Transcript written on _region_.log.
>
> TeX Output exited as expected with code 1 at Tue May 21 14:05:44
> Running `Preview-PDF2DSC' with ``pdf2dsc "_region_".pdf "_region_.prv/tmpfwHa4X"/preview.dsc''
>
> Preview-PDF2DSC finished at Tue May 21 14:05:49
> Running `Preview-Ghostscript' with ``"c:/texlive/2019/bin/win32/rungs.exe" ^"-dOutputFile=^(_region_.prv/tmpfwHa4X/pr1-^%d.png^)^" "-q" "-dDELAYSAFER" "-dNOPAUSE" "-DNOPLATFONTS" "-dPrinted" "-dTextAlphaBits=4" "-dGraphicsAlphaBits=4" "-sDEVICE=png16m" "-r121.034x120.663"''
>
> Preview-Ghostscript finished at Tue May 21 14:05:52
>