Invalid glyph found, continuing..
The output of the render-farm might be spammed with:
** Message: 17:17:33.849: Invalid glyph found, continuing...
** Message: 17:17:33.849: Invalid glyph found, continuing...
** Message: 17:17:33.850: Invalid glyph found, continuing...
** Message: 17:17:33.850: Invalid glyph found, continuing...
** Message: 17:17:33.850: Invalid glyph found, continuing...
** Message: 17:17:33.850: Invalid glyph found, continuing...
It's a bug in Inkscape: https://gitlab.com/inkscape/inbox/-/issues/8471
I open a ticket here to keep a reminder and an eye on this upstream issue.