Comment #46 continued:
If %LANG% (aka $LANG) is not set in the CMD shell, then the first instance has no LANG in the environment (as read by Python), the second inkscape instance launched from within Inkscape does have $LANG set to the system language (tested with en_US as well as with de_CH as current user's default language via Settings dialog).
Comment #46 continued:
If %LANG% (aka $LANG) is not set in the CMD shell, then the first instance has no LANG in the environment (as read by Python), the second inkscape instance launched from within Inkscape does have $LANG set to the system language (tested with en_US as well as with de_CH as current user's default language via Settings dialog).