[Inkscape-user] Why this error is happening? Browser does not open correctly an SVG file which is fine in Inkscape

Hello,

this is my first SVG file created from scratch in Inkscape. It has 6 layers just because i decided it should be good to keep some parts in separated layers to make final adjusts eventually easier.

But after i finished, i opened the attached file in my browser, and it only shows the black rectangle and the skin line which borders the whole story. Why all the text does not appear there?