BMP to PNG conversion shows incomplete image

[Anja]

Hi,
I'm having a problem with a BMP-file, I hope you can download from following link.
https://send.firefox.com/download/e2d65 ... I0hUTok4fg

I always use the same command
nconvert -dpi 300 -out png -merge_alpha -o outputpath\out.png -xall

But in this case the resulting image is incomplete, it shows only parts of the image. It's as if the original file contains layers, but since when would a BMP contain layers?

Thanks in advance
Anja

[xnview]

you have an alpha channel, if you want to remove it use -truecolors