You could try and save your image from inkscape to a high resolution PNG image… let’s say 8000pixels (height or width, or both if it is square)… then head over to:
upload it there and get it converted (into an SVG)…
…download, and there you go.
just a thought, since it always worked for me without issues.
edit: on a side note… your vector is rather detailed and therefore contains a LOT of data… I think the conversion into SVG (whatever algorithm is uses) may limit the lines of coordinations to whatever canvas size (or document size) you are using in Inkscape… I have no idea about Inkscape but I could imagine that it asks you what the dimensions of your project are at project creation and the SVG converter/exporter keeps a certain ratio in consideration… If that is true, you would need to have a rather huge canvas/document for the amount of detail (shapes/silhouettes) which you have created there. Also, maybe the exporter configuration lets you choose the amount of shapes and it was set too low.