Hi Anuja
on this mailing list the standard is bottom posting and
trim (a.k.a remove everything that is not pertinent).
See below

On 13.02.2021 15:53, Anuja Chanana via Cygwin wrote:
> 
>> Dear Cygwin Users,
>> Whenever I try to launch the Xserver on Cygwin using the command startx,
>> the following error appears
>>
>> /usr/bin/twm: warning: font for charset ISO8859-5 is lacking.
>> /usr/bin/twm: warning: font for charset KOI8-R is lacking.
>> /usr/bin/twm: warning: font for charset ISO8859-7 is lacking.
>> /usr/bin/twm: warning: font for charset JISX0208.1983-0 is lacking.
>> /usr/bin/twm: warning: font for charset KSC5601.1987-0 is lacking.
>> /usr/bin/twm: warning: font for charset GB2312.1980-0 is lacking.
>> /usr/bin/twm: warning: font for charset JISX0201.1976-0 is lacking.
>>
>> How to solve it?
>>
>> Looking forward to hearing from you.
>>
>> Thanks,
>> Anuja
> 
> 
> $ cygcheck -p ISO8859-5 |grep font
> ...
> font-util-1.3.2-1 - font-util: X.Org font utilities and font maps
> ...
> xorg-x11-fonts-misc-7.5-4 - xorg-x11-fonts-misc: X11 core fonts
> 
> Regards
> Marco

 > Hi Marco,
 > Thanks for the reply.
 > I installed  font-util-1.3.2-1 and  xorg-x11-fonts-misc-7.5-4. Still, the
 > warning pops up.
 >
 > Any idea why does that happen?
 >
 > Anuja

the warning is due to "twm" not being a UTF-8 application aware.

A solution [1] is to modify the call to "twm" as

    LC_CTYPE=en_US /usr/bin/twm

attached the ".Xclients" to be copied on your home directory
to do so.

After that, "startx" should not report anymore warning from "twm".

Be aware that usually on Cygwin the "startxwin" script provide a 
different Window Manager more "modern" than TWM provide by "startx".

[1] 
https://www.linuxquestions.org/questions/slackware-14/problems-with-twm-utf-8-a-4175435922/