Hi,
I don't know why but I was working with a version that had all the media files inside a /images/ folder but seems it's not this way anymore (or maybe I was wrong from the start...)
Anyway, it's solved now
https://github.com/FreeCAD/FreeCAD/pull/1653
PR #1653 Start WB quick fix for "New file" thumbnail
PR #1653 Start WB quick fix for "New file" thumbnail
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