What are the black rectangles that show up in the icon preview of my ubuntu (thurnar) file browser? See the image? You can see the file preview on the left has black rectangles. I don't see them on my drawing... [img]https://drive.google.com/open?id=1lWQUyxpZzmQM1VFL3GM7W6y4djikMBNJ
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Hi.

Usually flowed texts are rendered as plain black since that's not an svg feature yet. This case it's not so obvious. Would need to examine the svg file.
Hard to tell from a screenshot. Maybe the drawing too complex could also be a factor but I have some doubts about it.

One way to find mystery objects is to use Menu: View>Display Mode>Outline. There might be empty flow-text objects, or other non-contributing objects.

As stated above, sharing an example svg file would help us evaluate.