python setup.py install

starts and after some seconds it stops at:

C:\Users\Admin\AppData\Local\Programs\Python\Python36-32\Scripts\msgfmt.exe -o build\locale\zh_CN\LC_MESSAGES\picard-countries.mo po\countries\zh_CN.po
C:\Users\Admin\AppData\Local\Programs\Python\Python36-32\Scripts\msgfmt.exe -o build\locale\zh_TW\LC_MESSAGES\picard-countries.mo po\countries\zh_TW.po
C:\Users\Admin\AppData\Local\Programs\Python\Python36-32\Scripts\msgfmt.exe -o build\locale\da\LC_MESSAGES\picard-attributes.mo po\attributes\da.po
(null):po\attributes\da.po:18: keyword "msgctxt" unknown
(null): po\attributes\da.po:18:8: parse error
(null):po\attributes\da.po:26: keyword "msgctxt" unknown
(null): po\attributes\da.po:26:8: parse error
(null):po\attributes\da.po:33: keyword "msgctxt" unknown
(null): po\attributes\da.po:33:8: parse error
(null):po\attributes\da.po:38: keyword "msgctxt" unknown
(null): po\attributes\da.po:38:8: parse error
(null):po\attributes\da.po:43: keyword "msgctxt" unknown
(null): po\attributes\da.po:43:8: parse error
(null):po\attributes\da.po:48: keyword "msgctxt" unknown
(null): po\attributes\da.po:48:8: parse error
(null):po\attributes\da.po:53: keyword "msgctxt" unknown
(null): po\attributes\da.po:53:8: parse error
(null):po\attributes\da.po:58: keyword "msgctxt" unknown
(null): po\attributes\da.po:58:8: parse error
(null):po\attributes\da.po:63: keyword "msgctxt" unknown
(null): po\attributes\da.po:63:8: parse error
(null):po\attributes\da.po:68: keyword "msgctxt" unknown
(null): po\attributes\da.po:68:8: parse error
(null): too many errors, aborting
error: command 'C:\\Users\\Admin\\AppData\\Local\\Programs\\Python\\Python36-32
Scripts
msgfmt.exe' failed with exit status 1

What can I do?

BTW: 

python setup.py install --disable-locales

seems to do exactly the same, including above error messages.