When I save a Inkscape-file in SVG-Format, everything is alright. But when I save the file in PNG-Format I loose the layer "flames" (in filter-section).
So how can I save the flame-effect in a right manner (which format).
Well, it's hard to say for sure, without seeing the image. But chances are, this will help -- try using File menu > Export Bitmap instead of Save As Cairo png